Summary

The Battle of Antietam (ænˈti təm), also called the Battle of Sharpsburg, especially in the Southern states, was the decisive battle of the Confederate Maryland Campaign during the American Civil War. It took place on September 17, 1862, along the Antietam River near the town of Sharpsburg, Maryland.

It is considered the most important battle in the Eastern theater of the war in 1862. General Robert E. Lee had led the Northern Virginia Army into Northern territory for the first time in the Maryland Campaign after the failure of the Union Peninsula Campaign and the Confederate victory at the Second Battle of Bull Run. There it was again opposed by the Army of the Potomac under Major General George B. McClellan. By chance, detailed operational plans of Lee's fell into McClellan's hands before the battle, showing the enemy's vulnerability. However, he missed several opportunities to exploit the advantage.

Therefore, although McClellan's troops were still able to force the Confederates into a temporary retreat in the end, with heavy casualties, the Battle of Antietam did not bring a decision to the eastern theater of the war, but is considered a missed opportunity for the Union to inflict a crushing blow on the Northern Virginia Army and bring an early end to the Civil War. It was the highest casualty one-day battle of the entire Civil War. Because of some 3,600 casualties and total losses of about 23,000 men, September 17, 1862, is also known as the "bloodiest day in American history."

At the same time, its outcome signified a strategic victory for the Union, as it is considered by leading historians to be one of the most important turning points of the war politically. For even if the military success of the Union troops had ultimately been limited, the dearly bought victory nevertheless opened up the possibility for Lincoln to announce his Emancipation Proclamation to free the slaves in the southern states from a position of strength, undermined efforts by Great Britain and France to bring about a negotiated peace with an amicable division of the United States, and helped Lincoln's Republican Party to avert a threatened defeat in the congressional elections in the fall of 1862.

Antietam was the first place where the aftermath of a Civil War battle was documented in detail in photographs. Alexander Gardner's photographs of dead soldiers, presented by Mathew Brady in his exhibition The Dead of Antietam in New York at the end of 1862, shocked many viewers and led to a more realistic assessment of the hitherto idealized events on the battlefields.

Military situation at the beginning of the year

In the second calendar year of the American Civil War, much of the Union (Northern) effort in the important theater of war in the East continued to focus on capturing and occupying Richmond. The fall of its capital, located only 100 miles (160 kilometers) as the crow flies from Washington in Virginia, would, it was hoped in the North, deal a crushing blow to the Confederacy (Southern states), collapse the government of Confederate President Jefferson Davis, and render null and void the secession of the South, which was considered a "rebellion." To achieve these war aims, however, the Union had to go on the offensive, while the Confederates could confine themselves to defending their own territory.

An obstacle on the road to Richmond was formed by a series of smaller and larger rivers that ran parallel to the Virginia border between it and the Confederate capital. Initial attempts to capture Richmond, then, had failed in the early stages the previous year with Union defeats at the First Battle of Bull Run (July 21, 1861) and the engagement at Balls Bluff on the Potomac (October 21, 1861). Since then, General Joseph E. Johnston's Confederate army, standing between Manassas and Centreville, had been able to hold off the numerically vastly superior Union Army of the Potomac from making any advances into Virginia. The result was a stalemate that bothered the North more than the South.

Major General George B. McClellan, commander-in-chief of the Army of the Potomac, had demonstrated his organizational talents between the summer of 1861 and early 1862, turning a defeated army into a well-structured one with renewed self-confidence. As a result, the press had elevated him to the status of "young Napoleon." In fact, he was a procrastinator and perfectionist who shied away from risks and - even confronted with clearly inferior units - constantly pressed for further reinforcements of his own troops and better preparations before their deployment. McClellan tended to overestimate the numerical strength of the enemy (often many times over) and to use the miscalculation to justify his lack of initiative. This made him vulnerable to attacks from political opponents, who sometimes even insinuated that he was sympathetic to the Southern cause. Among his troops, the charismatic general was nevertheless very popular.

As brief commander in chief of the U.S. Army in the winter of 1861, McClellan achieved

Attempts by several Confederate armies to halt a further Union advance in Tennessee ended in defeat at the Battle of Shiloh (April 6-7), the Civil War's heaviest-loss battle to that point. Union armies subsequently captured Corinth, a railroad junction in northern Mississippi (April 30). The fall of Confederate positions and towns along the Mississippi River such as Island No. 10 (April 7), New Orleans (April 24), Baton Rouge (May 9), and Natchez (May 12) completed the series of Union military successes in the winter and spring of 1862.

This development made the disappointments of 1861 forgotten and renewed the hope from the beginning of the Civil War that the Southern rebellion could be ended within a few weeks. At the same time, the voices of the pessimists increased in the Southern states. Confederate Vice President Stephens declared privately as early as February 1862, "The Confederacy is lost."

Peninsula Campaign and Second Battle of Bull Run

Urged by Union President Abraham Lincoln to go on the offensive, General McClellan devised a plan in early 1862 to bypass Johnston's supposedly superior force and Virginia's running waters. To do so, his army was to be transported by ships across the Chesapeake Bay to the eastern shore of the state and from there march on the Confederate capital. Lincoln consented to the scheme, although he would have preferred McClellan to attack Johnston's army standing near Washington at Bull Run instead of going directly against Richmond.

McClellan's campaign began on March 17 with the landing of initial units of the 120,000-man Army of the Potomac at the tip of the Virginia Peninsula, about 100 kilometers from Richmond. The Union advance quickly came to a halt, however, with the month-long siege of Yorktown (beginning April 5). This allowed Johnston ample time to withdraw his force, now called the Army of Northern Virginia, to protect Richmond. Only after a Union victory at Williamsburg (May 5) could the Army of the Potomac advance further. Richmond now appeared seriously threatened. Johnston's attempt to stop McClellan with an attack five miles from the city failed due to the undecided outcome of the Battle of Seven Pines (May 31-June 1), in which Johnston was moreover seriously wounded.

The supreme command of the Army of Northern Virginia now passed to General Robert E. Lee. He had served as military advisor to President Davis since March 1862 and had helped conceive Major General Thomas "Stonewall" Jackson's Shenandoah campaign, which had brought the first significant Confederate successes in 1862. McClellan expected Lee to take a defensive posture, but he decided to attack the Union army. Almost all of the fighting in the ensuing Seven Days' Battle (June 25-July 1) resulted from attacks by the numerically outnumbered Confederates. Although Lee's complex attack plans mostly failed and his army suffered heavy casualties, McClellan was impressed by the enemy's variant offensive. He withdrew his troops to the James River, where they remained idle for the remainder of July.

McClellan demanded reinforcements from Washington to counterattack the supposed 200,000-man Northern Virginia Army - a threefold overestimate of its size. As he continued to ramp up his demands, an unnerved Henry Wager Halleck, the new commander in chief of the U.S. Army, ordered a withdrawal from the peninsula in early August. McClellan was to unite his Potomac Army, which still had 90,000 men, as quickly as possible with the 40,000-man Virginia Army under Major General John Pope, which had meanwhile advanced into northern Virginia. Lincoln had allowed the new major Union force to form and deploy on the Potomac only in June because he felt that the city of Washington was inadequately protected as a result of McClellan's campaign. The reluctant McClellan was uncertain whether he or Pope would command the combined army. Therefore, he secretly hoped for a defeat of his rival against several divisions Lee had sent to fight the Virginia Army under the command of Jackson. McClellan, meanwhile, took his time shipping his own army back.

Jackson scored an initial success against part of Pope's forces at the Battle of Cedar Mountain on August 9. With the withdrawal of McClellan's army looming, Lee left 22,000 men to defend Richmond and rushed to Jackson's aid with the rest of the Northern Virginia Army. He was determined to provoke Pope to battle with his total of 55,000 men before the latter's Virginia Army could unite with the entire Army of the Potomac.

Sent out by Lee to disrupt Union supply lines, Jackson's divisions raided and destroyed a large Union camp at Manassas Junction on August 27. Pope now decided, with expected reinforcements from four divisions of the Army of the Potomac and two divisions withdrawn from North Carolina, to face Jackson before he could reunite his forces with Lee's. Due in no small part to Pope's confused command of units from three armies that had never fought together, however, Union forces suffered a humiliating defeat at the Second Battle of Bull Run (August 28-30) and were forced to retreat across Maryland to Washington. McClellan had prevented other waiting divisions of the Army of the Potomac from coming to Pope's aid, despite Halleck's orders to the contrary.

"Hard" warfare and slave liberation

The turnaround in the military situation between March and August 1862 was dramatic. Whereas the Union had hoped to end the war quickly in the spring, both major Union units in the eastern theater of war had suffered heavy defeats in the summer. The failure of the peninsular campaign was repeatedly compared with Napoleon's fiasco in Russia. The Union also suffered setbacks in the western theater of war in the summer of 1862, although these were not as momentous. Moreover, the Northern Virginia Army, strengthened under its new commander-in-chief Lee, threatened to advance into the northern states for the first time and even attack Washington, Baltimore, or Philadelphia. While in the Southern states, after months of largely depressing news from the battlefields, a new confidence prevailed, in the Union states the certainty of victory turned into astonished horror, sometimes even panic.

In the North, domestic political antagonisms intensified, partly because congressional elections were coming up in the fall. The "War Democrats," i.e., those members of the Democratic Party who approved of the war in principle but criticized the attitude of the ruling Republicans as too intransigent, found themselves in a quandary. They attacked Lincoln because McClellan, himself a Democrat, had not received the requested reinforcements. For their part, many Republicans and newspapers supporting them, such as the New York Times, cast doubt on McClellan's account of the balance of forces on the Peninsula, accusing the commander-in-chief of the Army of the Potomac of a lack of will to fight, of treating the civilian population in Virginia too gently, or even of treason in light of his behavior toward Pope. The criticism was shared by some leading officers of the Army of the Potomac.

Although President Lincoln was deeply angered by McClellan's inaction since the Seven Days' Battle, he resisted appeals from his cabinet to dismiss the general or even bring him before a war tribunal. Instead, in early September, he asked McClellan to continue leading the Army of the Potomac, united with the deposed Pope's forces, and to protect the city of Washington from the feared Lee siege. Strong opposition from his ministers was met by Lincoln saying, "McClellan has the army on his side we must use the tools we have."

Doubts about McClellan's loyalty were exaggerated, but he did indeed disapprove of the hard-line war course of Radical Republicans, whom he suspected of having an outsized influence on the despised Lincoln. Like almost all Democrats, McClellan opposed above all turning the war for national unity into a fight against slavery in the Southern states. With his help, supporters of the general spread rumors that effective military leadership, and thus early victory with few casualties and no Confederate humiliation, would be sabotaged by men like Secretary of War Edwin M. Stanton until the more radical war aims could gain public acceptance.

Personally, Lincoln viewed slavery as a moral evil. In his first year in office, however, he had opposed the demands of prominent abolitionists and individual party members to make the freeing of slaves in the South a war goal. The president feared above all that this would lead to the secession of the four slave states that had remained loyal to the Union, the border states of Maryland, Delaware, Kentucky, and Missouri. On the other hand, the exploitation of slave labor played an important role in the war economy of the South. Early on, therefore, the practice of treating runaway or captured slaves from the Southern states as spoils of war that would not have to be returned to their "owners" had become established in the Union Army. The Republican-dominated Congress had signed this procedure into law on March 13, 1862.

During the summer of 1862, Lincoln became convinced that the old Union of slave and non-slave states could not be restored because of the strengthening of Confederate resistance. The final abolition of slavery was to be the basis of a new Union, and the Southern states were to be forced to accept it by any means available, including harsher treatment of the civilian population. In changing course in this way, the president was determined to disregard countervailing advice from military leaders such as McClellan and from representatives of the slave states of the Union (whom he sought to persuade to voluntarily abandon slavery).

On July 22, Lincoln opened to his astonished cabinet that he had come around to issuing a proclamation emancipating slaves in the Confederate states (though not in Union states), based on his rights as commander in chief in time of war. Almost all ministers supported the change of course, but Secretary of State William H. Seward warned of the possible diplomatic consequences. There was speculation in Europe that the Union would have to pin all its hopes on an uprising of slaves in the Southern states in view of recent reverses. Therefore, he said, a declaration of emancipation before a major Union military victory might be seen as "the last measure of a spent government, a cry for help," "our last cry in retreat."

In light of Seward's warning, Lincoln decided to shelve the Emancipation Proclamation for the time being. Only the victorious outcome of the Battle of Antietam two months later gave the opportunity to publish it.

Threat of diplomatic recognition of the Confederacy

Recent Union defeats threatened to have serious foreign policy consequences for the United States in the summer and fall of 1862.

From the beginning of the Civil War, the Confederacy hoped for recognition of its independence by the major European powers, Great Britain and France, and even for their subsequent military intervention in favor of the South. The textile industries of both countries, which had officially declared their neutrality, were dependent on cotton imports from the Southern states, and the Confederates organized a unilateral export embargo early on to exert economic pressure on the Europeans. In Britain, many leaders felt a connection to the "aristocratic" lifestyle of Southern plantation owners, but viewed the slave economy as a stain that stood in the way of recognition. On the other hand, it was pointed out that even the Union had not officially made the abolition of slavery a wartime objective, so it was not a mandatory precondition for establishing diplomatic relations with the Confederacy.

In Europe, people were skeptical about the Union's ability to militarily subdue the vast territory of the southern states, but shied away from an early commitment to one side. Although Emperor Napoleon III was inclined toward recognition from the beginning, he wanted to act in this regard only in agreement with the British government. In London, however, Prime Minister Palmerston let it be known as early as 1861 that the Confederacy could only expect recognition if it proved its viability through victories on the battlefields. Charles Francis Adams, Lincoln's ambassador in London, repeatedly warned his government of the dramatic consequences that could result from further Union defeats.

The worsening cotton crisis and the successes of Jackson and Lee in the Shenandoah Valley and off Richmond actually renewed appeals in Europe for recognition of the Southern states in the summer of 1862. President Lincoln, who considered the western theater of the war more important than the eastern, expressed his displeasure at what he saw as a distorted perception of the war situation abroad.

In a debate on July 17, the British Parliament was only dissuaded from calling for a peace settlement on the basis of a partition of the United States by an intervention of the prime minister. However, Palmerston himself changed his position shortly thereafter. On August 6, he wrote to Queen Victoria that Britain should soon propose an armistice. On September 24 (before news of the Battle of Antietam had reached London), he agreed with Secretary of State John Russell to launch a negotiated peace initiative between the North and South, agreed with France, in October. If Washington rejected this, London would unilaterally recognize the Confederacy.

Motives and starting position

After the Second Battle of Bull Run, heavily war-torn Northern Virginia offered no resources to sustain the victorious Confederate forces for any length of time. General Lee's only options were to withdraw his army to the Shenandoah Valley and interior Virginia, respectively, or to lead it across the Potomac into Union territory in Maryland. In a letter to Jefferson Davis on September 3, 1862, Lee advocated the latter option and, firmly expecting a positive response from the president, began crossing the border river with his army the very next day. The longer the war lasted, Lee believed, the more the Union's structural advantages, such as its larger population and the presence of modern industry, would come into play. Therefore, the Confederate Army would have to strike a decisive blow before it was too late.

Lee knew that Virginia politicians and newspapers had long advocated taking the war north. In addition to the psychological aspect of demonstrating the viability of the Confederacy to the Union and European powers, he also hoped for concrete political results from continuing his offensive: he hoped that the people of the slave state of Maryland would welcome his troops as liberators from the "yoke of the North" and that able-bodied men would join the Army of Northern Virginia. To promote this, Lee had his troops sing the propaganda song Maryland, My Maryland (sung to the tune of "O Tannenbaum") as they marched, calling on the people of the state to join the Confederacy.

Lee also speculated that the northern incursion might weaken the Republican position, encourage the election to Congress of "Peace Democrats," also known as "Copperheads," who increasingly advocated an end to the war, and thus prepare for an amicable dissolution of the Union. If the campaign was successful, an advance into Pennsylvania would be possible, where Lee intended to destroy a key railroad bridge over the Susquehanna, thus cutting the line of communication to the western theater of the war. Meanwhile, a Confederate campaign in the north would prevent a new Union incursion into Virginia and allow defensive lines to be extended there and crops to be harvested undisturbed. Meanwhile, because of the strong numerical superiority of the Army of the Potomac, which had retreated to Washington, Lee did not plan the siege of the Union capital feared in the North.

Hopes of backing the Northern Virginia Army in Maryland soon proved illusory. In the western part of the state, where the advance was made, there were few slaves and the population (often of German origin) was largely Unionist. The appearance of Lee's army did nothing to change this attitude. After months of marching and fighting, the soldiers were starving and starved of dirt, their uniforms ragged, often not even wearing shoes. Eating unripe corn and fruit from Maryland's fields and gardens caused repulsive diarrhea in many of the men. The condition of the Northern Virginia Army was so bad that within a week nearly one-fifth of the soldiers (10,000 out of 55,000) deserted to fight their way back to Virginia. A contributing factor was that many Confederate soldiers supported the defense of their homeland but refused an offensive in the North. Draconian punishments only partially stopped the bloodletting. Looting did the rest to turn Marylanders against the Confederates. The pitiful appearance of Lee's army became a popular subject for commentators and cartoonists in the North.

Meanwhile, on the Union side, Lincoln's confidence in McClellan paid off - at least briefly. Still popular with the troops, the general succeeded in a limited amount of time in reorganizing the Union forces, incorporating the divisions defeated at Bull Run into the Army of the Potomac, and preparing it again for campaign. On September 7, just ten days after Bull Run, the first of McClellan's units left Washington to join the Army of Northern Virginia. The initially subdued mood in the ranks lifted in the face of a friendly, at times enthusiastic, welcome from the Maryland populace that had not been anticipated. Until then, the Army of the Potomac had operated mainly in enemy territory, and support from the local population was a new experience for most Union soldiers.

"Lee's Lost Orders" and First Battles

The Northern Virginia Army's advance into Maryland isolated two western Virginia towns with important Union garrisons: Harpers Ferry (with 10,500 troops) at the mouth of the Shenandoah River on the Potomac, and Martinsburg (with 2500 troops) farther west. McClellan wanted the garrison to vacate the bases and join the Army of the Potomac, a move Lee expected. Army Commander in Chief Halleck, however, forbade the evacuation. Lee then decided to attack the Union garrisons in the rear of his army, partly because he hoped to capture food and equipment in large quantities at Harpers Ferry.

On September 9, Lee issued his "Special Order No. 191" at Frederick, breaking his army into four parts. Three divisions under "Stonewall" Jackson were to make a wide sweep across Martinsburg and attack Harpers Ferry from the west. Divisions under Major General Lafayette McLaws and Brigadier General John George Walker were to take the hills east (in Maryland) and south of the town (in Virginia), respectively, and bombard the garrison with artillery from there. Lee planned to hold the Maryland position with the remaining units west of Frederick between Hagerstown and the South Mountain range. According to Lee's optimistic planning, the four army components were to rejoin after only three days.

As was so often the case, Lee took a big risk in this division of a weaker army. Meanwhile, he relied on McClellan's timidity, demonstrated in recent months, and assumed that the Army of the Potomac would not be ready for action again before three to four weeks had elapsed.

McClellan's army, however, reached Frederick on the morning of September 13, three days after Lee's departure, and was tumultuously acclaimed by the local populace. Shortly after arriving, a sergeant resting outside the village came across a copy of Lee's "Special Order No. 191" addressed to Confederate Major General D. H. Hill, which had been wrapped as wrapping paper around three cigars and carelessly left on the grass. The significance and authenticity of the paper were soon recognized and "Lee's Lost Orders" ("Lee's Lost Orders") were brought to McClellan. The commander-in-chief of the Army of the Potomac was presented with a unique opportunity: should he get his army on the march quickly enough, it was possible to separate and defeat the various parts of Lee's army. In a telegram to President Lincoln, McClellan announced, "I have the plans of the rebels and will catch them in their own trap."

The reluctant McClellan, however, allowed 18 hours to elapse before moving his army. Moreover, Lee very soon learned of unusual activity at McClellan's headquarters through an informer of Major General J.E.B. Stuart, the commander of his cavalry. He now expected an advance on the three passes on South Mountain. There was ample time for him to reinforce the Confederate positions there in such a way that in the fighting at South Mountain on 14 September the advance of two Union corps could be held up until nightfall. Only at South Pass did the Union VI Corps under Major General William B. Franklin make a breakthrough in the afternoon.

The Northern Virginia Army lost nearly a quarter of its soldiers not at Harpers Ferry at South Mountain. The losses were so great and the prospect of continuing to defend the remaining passes so remote that Lee decided on the very evening of September 14 to abandon the Maryland campaign and cross the Potomac into Virginia at the small town of Sharpsburg the following day. McClellan telegraphed to Washington that his army had won a glorious victory and that the Confederates were retreating in panic. Lincoln replied on September 15: "God bless you and all who are with you. If possible, destroy the rebel army."

Franklin was unable to fulfill McClellan's order to come to the aid of the threatened garrison at Harpers Ferry because of his slow action. The garrison surrendered to Jackson on the morning of September 15, three days later than Lee had calculated. It was the largest surrender of Union troops during the Civil War. Jackson's "spoils" included at least 500 escaped from slavery who were now carried back to the South. Meanwhile, a Union cavalry unit that had managed to break out of Harpers Ferry on September 14 fell into the hands of large quantities of Confederate ammunition supplies, which they subsequently carried to safety in Pennsylvania.

Deployment of both armies

General Lee and his troops reached Sharpsburg early in the morning of September 15. There he received a belated message from Jackson speaking of the imminent fall of Harpers Ferry. Instantly Lee changed his attitude about withdrawing from Maryland and decided to join the Army of the Potomac for battle at Sharpsburg. He trusted that the other Confederate units could march there in time.

Lee set up his headquarters in a tent west of the village and placed his troops in a line about 6.5 kilometers long on a ridge of hills east of Sharpsburg, where the approach of the Army of the Potomac could be expected. A tree-lined little river running north-south in a winding line, the Antietam, would act as a natural barrier here to impede the advance of the Union soldiers. However, the Antietam was only about 18 meters wide in some places, partially shallow and fordable, and crossed by three stone bridges, each 1.5 kilometers apart.

The hills provided a favorable, if not perfect, defensive position. Southwest of Sharpsburg, steep slopes with good defensive positions extended close to Antietam. Northeast of the town, the terrain opened up, the hills flattened out, and fields and meadows extended to Antietam, guaranteeing a clear field of fire except for a few intervening groves. Along the Confederate lines, fences, limestone ledges, and natural or artificial depressions in the terrain provided cover for the soldiers. To the west of the positions also ran a well-maintained road, the Hagerstown Turnpike, over which troop movements could be made if necessary.

Despite these generally favorable topographical conditions, Lee took a great risk at Sharpsburg. In the rear of his army flowed the Potomac, leaving little room for maneuver. Moreover, in the event of a retreat, the Northern Virginia Army would have had only one ford available-Boteler's Ford on the way to the Virginia town of Shepherdstown, southwest of Sharpsburg. To save his Maryland campaign, however, Lee was willing to take another risk.

Lee learned about the fall of Harpers Ferry, 20 kilometers south of Sharpsburg, about noon on September 15. He hoped that Jackson's divisions would now march in haste to reinforce the weakened main force of the Army of Northern Virginia. Initially, however, only two divisions under the command of Major General James Longstreet and Major General D.H. Hill's division were available to Lee at Sharpsburg-a total of about 18,000 men. Lee countered his officers' concern that with this number of troops he would be hopelessly outnumbered by the Potomac Army, which was more than three times as strong, by predicting that the cautious McClellan would not attack until the day after next.

Lee was to be proved right. An advance guard of the Army of the Potomac did reach the vicinity of Sharpsburg on the afternoon of September 15, but it took all of the following day for McClellan's sedately advancing troops to take up positions at Antietam. Around noon on September 16, the first Confederate troops who had participated in the siege of Harpers Ferry began to arrive at Sharpsburg. At that point, only 25,000 Confederates faced the 69,000 Union soldiers who were within 10 kilometers east of Sharpsburg. McClellan, however, implied that Lee might have three times that number at his disposal.

McClellan occupied as his headquarters the house of Phillip Pry, a wealthy farmer, which was situated on a knoll east of Antietam. From here he had a telescopic view of the northern and central portions of the eventual battlefield. He planned to maintain contact with his commanders by means of flag signals transmitted from a wooden tower. McClellan spent most of September 16 preparing an attack for the following morning, but refrained from having the Northern Virginia Army's positions adequately reconnoitered, so Lee's weakness escaped him. In addition, McClellan personally attended to details of supply transport and troop deployment, wasting further precious time.

McClellan's battle plan and its implementation

General McClellan intended to strike the main blow on the left flank of the Army of Northern Virginia, northeast of Sharpsburg. The Confederate positions on the ridge here turned in a westerly loop to the Potomac, and this left the Union forces ample room to cross the Antietam and advance in the open ground between the creek and the hills. Attacking were to be four divisions of the I Corps of the Army of the Potomac under Major General Joseph Hooker and two divisions of the XII Corps under Brigadier General Joseph Hooker. Corps under Brigadier General Joseph K. Mansfield. The three divisions of the II Corps under Major General Edwin V. Sumner were to stand by east of Antietam to support the attackers if necessary.

At the same time, the four divisions of the IX Corps under Maj. Gen. Ambrose E. Burnside to attack the Confederate right flank in the south to distract from the main thrust in the north. McClellan expected Burnside's forces to advance across the Antietam and, if possible, in a wing movement, bypass the Army of Northern Virginia and block Lee's possible route of retreat across the Potomac at Boteler's Ford.

Little attention was paid by McClellan to the center of the Confederate positions in front of Sharpsburg, where the middle stone bridge was within range of enemy artillery and therefore difficult to cross. The three divisions of the V Corps under Major General Fitz John Porter were to stand by east of Antietam as a reserve to attack here in the event of a breakthrough by Union forces to the north or south of the battlefield. McClellan assigned the same function to the three divisions of the VI Corps under Major General Franklin, which were to arrive at Antietam during 16 September, and to the cavalry division under Brigadier General Alfred Pleasonton, which was part of Mansfield's corps.

McClellan's battle plan was, on the whole, well thought out, but required coordination of operations at the corps and division levels, which did not occur. For this, McClellan was personally responsible. Unlike General Lee, he stayed mostly near his headquarters, far from the battlefield, and therefore could react only belatedly to events on the ground. Instead of sticking with the usual division of the Army of the Potomac into three wings, he changed the command structure two days before the battle so that all corps commanders had to report to him personally but did not have to coordinate their operations with each other even when they deployed their troops on the same part of the battlefield. Rivalries among Union generals reportedly motivated the new structure. The problem was exacerbated because McClellan issued only individual orders, but no general order to explain the interrelationship of all operations.

The lack of coordination meant that more than 20,000 Union soldiers were never deployed at any one time during the Battle of Antietam, and Lee always had enough time to redeploy his own units to repel attacks. 20,000 Union soldiers, more than a quarter of the 75,000 available, were not engaged in combat at all. That McClellan held Pleasonton's cavalry division in reserve in the center and did not use it for reconnaissance and security on his flanks proved to be another serious oversight.

Because of these structural and tactical errors, the Union's two-to-one superiority in the battle was almost completely erased. McClellan's caution resulted, as it so often did, from miscalculation of the troops available to Lee at Antietam. Union officers estimated the strength of the Northern Virginia Army at Sharpsburg to be as high as 130,000 men.

Course of the Battle of Antietam

On McClellan's orders, the I Corps under Hooker crossed the Antietam about 4 o'clock on the afternoon of September 16. For this purpose the troops used the northern stone bridge and nearby fords that were beyond the range of Confederate artillery. Originally intended only to take up positions for the impending attack, Brigadier General George G. Meade's division encountered forward Confederate troops under Brigadier General John B. Hood in a copse (then designated "East Woods" on military maps) on the northeastern edge of the eventual battlefield. A fierce exchange of fire ensued, including artillery. There were casualties on both sides.

As darkness fell, the fighting subsided, but the artillery fire continued to cover the advance of McClellan's army. The engagement did not give the Union any advantage, but told Lee where to expect McClellan's attack in the morning and positions to be reinforced. McClellan also continued to make preparations for the attack during the night, and about midnight he ordered the XII Corps under Mansfield to take up the position. Corps under Mansfield to also cross the Antietam to support Hooker's corps.

Both commanders-in-chief ordered the division commanders remaining in the vicinity of Harpers Ferry to march hastily with their troops to Sharpsburg. Lee's orders went to Major General McLaws, to Major General Richard H. Anderson, and to Major General A.P. Hill, whose Light Division was still at Harpers Ferry, to guard captured Union soldiers there and to secure the spoils made. McClellan ordered Major General Franklin to bring in two of his three divisions. The arrival of all reinforcements by the following afternoon meant that the Army of the Potomac would have to take on Lee's entire Northern Virginia Army, which was at most 40,000 strong, on September 17, although the Union numerical advantage was still 2-1. McClellan had missed his second chance to deal a crushing blow to Lee's divided army on September 16.

Troops from both sides spent a restless night, disturbed by occasional exchanges of fire and by a light drizzle. Meanwhile, the approximately 1300 residents of Sharpsburg tried to get themselves and their possessions to safety. Many found shelter in the basements of their homes or in a large cave on the Potomac. Farmers did what they could to move livestock away from areas where fighting threatened the next day.

The actual Battle of Antietam began at dawn on September 17 at about 5:30 a.m., when General Hooker's I Corps advanced on the Confederate left flank, where the bulk of Jackson's II Corps dispersed at the height of another copse (West Woods). From there the Confederate positions extended in an arc to the terrain beyond the Hagerstown Turnpike. Jackson had about 7,700 men available at this point, Hooker about 1,000 more.

The Union troops attacked from northern and northeastern positions along the Hagerstown Turnpike, targeting a Southern artillery position located on a plateau east of this road. To the west of the Hagerstown Turnpike stood a small church nearby that had been built by the German-born pietist and pacifist sect of the Dunker (= Anabaptists, from the German Tunker). On the morning of the attack, ground fog made it difficult for Union soldiers to see, but the white-painted church building stood out well against the surroundings, marking the direction in which the attack by the Army of the Potomac was to be made. As the Union troops advanced, Confederate mounted artillery under J. E. B. Stuart opened fire. Union batteries, located on a ridge on the northern edge of the battlefield, fired back. Initial fighting occurred in front of the eastern grove, where a Confederate brigade was able to push back several Union regiments.

Most of the terrain between the Union troops and the Confederate positions was taken up by pasture land. However, right in the middle, north of the plateau, was a cornfield of about 8 acres in which the stalks were more than man-high. As they advanced, Union troops discovered by bayonet points flashing in the sun that Confederate soldiers were hiding in it. Hooker ordered the advance halted and this obscure section of the front fired upon with four batteries. The mutual artillery and rifle fire that developed was so intense that the cornfield was cut down as if with a scythe. Hooker later wrote in his report:

Union troops now advanced on a line some 800 yards long. Fierce exchanges of fire again occurred in front of the eastern grove, where a Union brigade advanced into the cornfield but was unable to break the resistance of an outnumbered Confederate brigade from Georgia. Union troops also met fierce resistance on their right flank, but were able to make terrain gains at the western grove and in the cornfield and gradually approached the plateau. The Hagerstown Turnpike was flanked by wooden gates, some of which were tall and could be used for cover, but also exposed the soldiers when they climbed over them, making them easy targets for snipers. As the terrain on both sides of the trail was heavily fought over that morning, the gates became a deadly trap for many soldiers.

Union soldiers had already moved close to the plateau south of the cornfield when Jackson's repulsed troops were reinforced by General John B. Hood's division. It had been held in reserve by Jackson because the soldiers were exhausted after the previous evening's fighting and should have been resting. Hood's men were reportedly angry and therefore especially motivated to fight the Union army because they had had to interrupt their first hot breakfast in days for their mission. They were able to push the enemy troops back through the cornfield, but suffered heavy casualties in the process. The division's 1st Texan Regiment lost 82% of its soldiers in just 30 minutes. Nevertheless, Hood's division's advance saved the Northern Virginia Army's left flank from collapse. The attack by Hooker's I Corps came to a halt.

McClellan had failed to have Hooker's attack supported by the two divisions of the nearby XII Corps. Mansfield's corps to support it. When the XII. Corps finally entered the fray from the eastern grove about 7:30 a.m., Hooker's troops were already too exhausted for the Union to gain a decisive advantage. General Lee had enough time left to counter the second Union attack wave by sending in three new divisions. Nevertheless, the XII. Corps again drove Hood's forces out of the cornfield, and a Union brigade was even able to capture the Confederate batteries on the plateau near Dunker Church during the attack.

In the meantime, however, Mansfield had been mortally wounded. Hooker was also hit in the foot by a Confederate sniper's bullet and had to be carried from the battlefield. The loss of the two commanding generals on the northern section of the front unsettled the Union forces, and the brigade on the plateau withdrew again from the western grove after heavy Confederate return fire. Command of the I Corps now passed to Brigadier General Meade, and command of the XII Corps to Brig. Gen. Corps to Brigadier General Alpheus S. Williams.

After three and a half hours of fighting, by 9 a.m., more than 8,000 men were already dead, wounded or missing on the northern front, with neither side gaining any significant advantage.

McClellan had initially held back the three divisions of the II Corps of the Army of the Potomac under Major General Sumner far to the east of the battle near his headquarters. Not until 7:20 a.m. did he send two of Sumner's divisions forward to the battlefield, where they did not arrive until an hour and a half later. Without coordinating his actions with Meade and Williams, Sumner ordered his two divisions, commanded by Major General John Sedgwick and Brigadier General William Henry French, to make a renewed attack on the Confederate left flank at about 9 a.m.. The enterprise was so precipitous that French's division lost the line as it advanced at the eastern grove. Apparently disoriented as to where to direct his troops, French ordered a left swing to bypass the plateau to the south. He thus inadvertently led his men to the middle Confederate positions in front of Sharpsburg, where no fighting had even taken place.

Sumner was thus left with only the 5,400 men of Sedgwick's division for his attack. These were able to advance almost unimpeded across Cornfield and Hagerstown Turnpike. The apparent Confederate retreat, however, proved to be a trap, for Jackson's troops, joined once again by fresh divisions, took the Union soldiers under fire from three sides simultaneously upon reaching the western grove. As soldiers in the Union rear feared hitting their own comrades, they became targets without being able to return fire. After less than half an hour, Sedgwick's division was forced to retreat. It suffered over 2000 killed, wounded and missing. Among the severely wounded was young Oliver Wendell Holmes, Jr. who would later rise to become a Supreme Court justice. A subsequent Confederate counterattack on the meadows in front of the western grove was met with Union artillery fire and had to be abandoned.

The last major fighting on the northern part of the battlefield occurred around 10 a.m., when two regiments of the XII Corps again attempted to implement Hooker's original plan. Union Corps again attempted to implement Hooker's original plan and advanced from the eastern grove toward Plateau and Dunker Church. The attack stalled because of Confederate opposition and lack of reinforcements, but the Union forces made minor gains in terrain between the cornfield and western grove.

This ended the first phase of the battle after four hours with more than 12,000 men lost, including two Union commanding generals. Five Union and four Confederate divisions were so badly damaged that they could not intervene in the rest of the day's warfare. McClellan's plan to roll up the left flank of the Northern Virginia Army had failed. Because the Union forces' attack was successive rather than a massive blow, the Potomac Army's strong numerical superiority on this part of the battlefield was not fully exploited at any point. The result was a series of losing battles over relatively small terrain that ultimately ended in stalemate. According to eyewitness accounts, the cornfield area alone had changed hands fifteen times that morning.

Meanwhile, fighting had also developed at the center of the Confederate positions in front of Sharpsburg, triggered not by an attack order from McClellan but by the error of Brigadier General French. When his division encountered Confederate skirmishers on a farm southeast of Dunker Church, he decided to take the fight here. Shortly after 9:30 a.m., word reached him from Major General Sumner, who informed French of the debacle of the Union forces at the western grove and ordered that an attack in front of Sharpsburg would compel the Confederates to withdraw troops from the north of the battlefield.

The center of the Northern Virginia Army positions was under the command of Major General Longstreet. The defenses were weak at this, because detachments had been moved during the morning to reinforce Jackson's corps. Since then the five brigades of Major General D. H. Hill's division held the position; three of them had already suffered casualties during the morning fighting. Two brigades occupied the best defensive position, entrenched 100 yards behind a ridge in a dirt road that ran in an arc between Hagerstown Turnpike and Boonsboro Road. Erosion and traffic from transport trucks had shaped it into a deep hollow way (called Sunken Road by local residents) that formed a natural trench. Artillery had not been placed in position on this section of the front from any side.

French hoped for an element of surprise as he commanded his division up the hill to the Sunken Road. This failed because the entrenched Confederates, seasoned veterans, anticipated the attack and patiently held their fire until the enemy reached the crest of the hill in a position where they could be easily hit. The leading Union brigade under Brigadier General Max Weber, composed mainly of German immigrants without much combat experience, suffered particularly heavy losses. It lost 450 men in just five minutes. A subsequent assault by Colonel Dwight Morris's similarly inexperienced second brigade was also repulsed. French now sent his last and best brigade into the fight, but it too failed in its attempt to advance to the Sunken Road. In less than an hour, French's division had thus lost nearly a third of its soldiers on the hill.

Meanwhile, the Confederate brigades on the Sunken Road received reinforcements on the right from Major General Anderson's division. Encouraged by this, the Confederates were preparing for a flank attack down the hill about 10:30 a.m. when the last of Sumner's divisions, commanded by Major General Israel B. Richardson, arrived on the scene. McClellan had held them back as the rest of Sumner's corps marched to the battlefield and did not send them off until 9 o'clock. Richardson ordered a renewed attack, but the famed Irish Brigade was also routed without reaching the Sunken Road.

By now it had become noon, and the repulse of four successive Union frontal assaults had also taken a heavy toll on the Sunken Road defenders. Anderson had been badly wounded early on (he succumbed to his injury four weeks later), and no one took command, so his division was not much help. The center of the defensive line proved especially weakened, where the hollow road made a sharp bend and the natural trench was so narrow that the Confederates were frequently hit by ricochets bouncing off the rear embankment.

When Confederate Brigadier General Robert E. Rodes gave orders to redeploy troops during the fifth Union assault to strengthen the center, a regimental commander misunderstood him and ordered a retreat from the Sunken Road. The four remaining regiments of the brigade joined the action, which degenerated into a wild rout, without Rodes being able to do anything about the collapse of the defensive line. The advancing Union soldiers then captured the Sunken Road and 300 Confederates. In many places on the hollow road, the dead were by now lying two or three on top of each other.

As the Union troops regrouped on the Sunken Road, they were attacked from the north by two Confederate regiments, but they suffered heavy casualties in the action and were forced to withdraw. While French's division secured the Sunken Road, Richardson's advanced on the new Confederate defensive line, which was less than 300 yards southwest on the property of farmer Henry Piper. Meanwhile, Major General D.H. Hill had rallied the remnants of his division, and it attacked the Union forces in a cornfield on the Piper farm. The weakened unit's advance, while doomed to failure, bought General Longstreet time to consolidate the Confederate line in front of Sharpsburg by massing guns; their fire halted the Union advance. An intact infantry was no longer available to Longstreet at this point. The remaining units were each barely larger than a few hundred men and in some cases had no ammunition left.

Reluctantly, due to Confederate artillery fire, Richardson withdrew his division, which had already lost over 1,000 men, to the hill north of Sunken Road. Here they awaited the arrival of requested guns to knock out Longstreet's artillery, but received only inadequate cannon that failed to reach the Confederate positions. While discussing the situation with a battery commander, Richardson was severely wounded by a fragment of shell about 1 o'clock and transported to McClellan's headquarters at Pry House, where he succumbed to his injuries six weeks later. Command was finally assumed by Brigadier General Winfield Scott Hancock, but in the meantime another favorable opportunity to break through the Confederate line, which was on the verge of disintegration, passed.

In three and a half hours, over five and a half thousand men had fallen, been wounded, or were missing in the closest vicinity of the front line section on Sunken Road, which was only 700 yards long. Casualties approached 2,600 Confederate men and nearly 3,000 Union soldiers. The slaughter earned the Sunken Road the new name Bloody Lane.

Despite its higher casualties, the Army of the Potomac had carved out an advantage in the center of the Confederate positions in front of Sharpsburg. In addition, McClellan still had two fresh corps at his disposal that could be used to attack the Army of Northern Virginia: the V Corps under Porter along with Pleasonton's cavalry division, totaling 13,800 men, and the 12,000-man VI Corps under Major General Franklin. Corps of the Union under Major General Franklin, which had arrived at Antietam about noon coming from Harpers Ferry and was now securing the Union line to the north on McClellan's orders.

Franklin wanted to launch a new attack at the western grove about 1 o'clock, but was held back by the older and senior corps commander Sumner, who was shocked by the incredible blood toll of the previous engagements. Another setback, Sumner reasoned, would put the entire Union right flank in jeopardy. McClellan at first leaned toward Franklin's view, but after consulting with both officers on the ground, changed his mind. He gave orders to make no further attacks in the north and center of the battlefield.

Southeast of Sharpsburg, IX Corps under Major General Burnside had been ordered to wait for an order from McClellan before launching what was intended to be a feint attack. By the time the order from headquarters finally reached Burnside at about 10 a.m., however, the fighting on the northern front had subsided and the original objective of the enterprise had become obsolete. Burnside, however, apparently still assumed that a diversionary maneuver was incumbent upon him and did not need to be tackled with full force. He did not realize (or was not told) that upon his troops now rested the brunt of the Union attack.

Burnside's 13,000 troops meanwhile faced fewer than 4,000 Confederates, the latter mainly in positions spread over what would later be called Cemetery Hill in front of Sharpsburg. Lee had withdrawn a division and an additional brigade from his right flank to repel Union attacks in the northern and central front.

Due to inadequate reconnaissance of the terrain, Burnside-unlike McClellan's experts the previous day-had missed a nearby ford that would have allowed Union infantry a comparatively easy crossing of the Antietam. Burnside therefore concentrated on capturing Rohrbach's Bridge, a nearly 40-meter-long, 3.70-meter-wide, three-arched stone bridge and southernmost crossing of the Antietam at Sharpsburg. It was defended by 550 forward-deployed sharpshooters from Georgia under the command of Brigadier General Robert A. Toombs. They spread out along the Antietam and took the bridge under fire from the safe cover of ledges, stone walls, and trees.

Even before the attack on the stone bridge began, Burnside sent three brigades to cross a ford a mile to the south that McClellan's scouts had also spotted the day before. When the troops reached the designated spot, however, they found that the bank there was too steep. Through dense brush, the men made their way further southwest in a lengthy maneuver, finally reaching Snavely's Ford, where a crossing was possible.

By now it had become noon and the Confederates had already repulsed two attacks on the stone bridge. McClellan lost patience and ordered Burnside to take the bridge even at the cost of heavy casualties. The third attack began about 12:30 p.m., and after about half an hour units of the IX Corps succeeded in establishing themselves at the east end of the bridge. The Georgia snipers ran out of ammunition, and word reached Toombs from the southern flank of the passage of Union units across Snavely's Ford. The Stone Bridge defenders then retreated toward Sharpsburg. Burnside's troops had been held up for three hours by a force outnumbered twenty to one and had suffered casualties more than three times those of Toombs's Georgians, 500 men.

The right flank of Lee's army was now in severe straits. Three of Burnside's divisions threatened to penetrate General Longstreet's weakened forces. But the approach of unspent units of the IX Corps, which had remained at some distance from the bridge, the transportation of supplies of ammunition, and the crossing of the narrow bridge proved to be protracted operations, costing Burnside two valuable hours (a ford discovered in the meantime north of the bridge remained unused). McClellan's anger in the face of these delays was directed at Burnside. He sent out several couriers to urge his general to proceed more vigorously.

The Potomac Army's faltering allowed General Lee ample time to shift troops and ordnance to his right flank from the other sections of the front, where fighting had since ceased. Briefly, the Confederates even contemplated a relief attack to the north of the battlefield, to be led by Stuart's cavalry. However, Jackson aborted the enterprise in the face of massive Union artillery superiority. Finally, after an eight-hour forced march from Harpers Ferry, the Light Division Hills arrived at Sharpsburg at about 2:30 a.m., to Lee's great relief. It had crossed the Potomac through Boteler's Ford, which remained open. Hill's men were ordered to reinforce Longstreet's troops.

As the Union IX Corps regrouped at the bridgehead on the west side of Antietam, Burnside deployed about 3 o'clock with 8,000 men for a two-winged attack on the Confederate right flank. The advance was initially successful and the defenders fell back toward Sharpsburg. Chaos reigned in the town itself in view of the many wounded being carried through the streets, numerous scattered soldiers whose units had been routed, and Union artillery fire that damaged a number of buildings so badly that they later had to be demolished.

With the intervention of Hill's 3,000-man division in the fight, the tide turned about 3:40. The Northern Virginia Army was able to move to counterattack and the extreme left flank of the Union IX Corps was placed in grave danger. Confusion arose among the Northerners because many of Hill's men were wearing Union blue uniforms that had fallen into their hands at Harpers Ferry. Burnside, upset by the surprising turn of the battle, withdrew his troops to Antietam. Although he had twice as many men as the enemy in the field, he was concerned that they would not be able to hold the elaborately fought bridge. He asked McClellan to send promised reinforcements in the morning. However, McClellan's fears had been renewed that Lee still had unimagined forces at his disposal. Shying away from the risk of running his reserves into a massive counterattack by the Army of Northern Virginia, McClellan sent Burnside only one battery.

That McClellan's fears were far from reality did not escape the notice of a battalion of the Union's V Corps held in reserve. During an advance across the middle stone bridge on the Boonsboro Road, the men discovered the vulnerability of the middle defensive lines near Sharpsburg. Brig. Gen. George Sykes, commanding the 2nd Division of the V Corps, urged that he be allowed to lead his men across the bridge into battle to assist Burnside. McClellan, however, who already seemed convinced of the proposal, desisted after consulting with Corps Commander Porter. Porter's statement survives from this conversation, "General, remember, I command the last reserve of the last army of the Republic!"

The Northern Virginia Army had been saved by the timely arrival of Light Division A. P. Hills. The IX Corps of the Army of the Potomac was left with no other task than to secure the stone bridge at Antietam, which had been captured with heavy losses. Because of what happened that day, the structure was later renamed Burnside Bridge or Burnside's Bridge.

Losses

Casualties in the Battle of Antietam were high on both sides. For the Union, 2,100 soldiers had fallen and 9,550 had been wounded; 750 Union soldiers were considered missing or had been captured. For the Confederates, 1,550 soldiers had fallen and 7,750 had been wounded, and 1,020 were considered missing or had been captured. Among those killed or mortally wounded were six generals, three each from the Union and Confederacy. In the days and weeks following the battle, at least 2,000 wounded died from their injuries.

To this day, September 17, 1862, is considered "the bloodiest day in American history." More Americans fell at Antietam in a single day than in any previous or subsequent war involving the United States. For example, the number of killed and wounded at Sharpsburg was four times the number of American casualties on D-Day during the Normandy landings in 1944. More American soldiers died on the battlefield at Antietam than in all other wars of the 19th century combined.

After the battle

General McClellan wrote to Washington the morning after the battle that fighting would probably resume the same day. However, even then he made no move to put this into effect, waiting instead for Lee's actions. The agreement of a truce with the Confederates to recover the wounded signaled that there would be no further fighting on September 18. With just the up to 13,000 reinforcements that arrived that day and his 20,000 soldiers who had not been deployed the previous day, McClellan would have had more fresh forces available to him in a new offensive than Lee even had soldiers left in the field. In addition, there were the 30,000 Union soldiers who had been uninjured in their combat mission the previous day. McClellan's decision against continuing the attacks, often criticized later, was in line with the attitude of most officers and soldiers in the Army of the Potomac.

Lee, for his part, did not initially withdraw his troops after a battle in which they were on the verge of defeat several times, despite the adverse circumstances. Instead, he even considered launching an attack on September 18. It was not until the night of September 19 that the Northern Virginia Army began its retreat into Virginia via Boteler's Ford. McClellan first sent a brigade to reconnoiter it by force, and on September 20 sent several regiments from Porter's V Corps after it. The troops deployed, however, were too weak to accomplish anything. In the engagement at Shepherdstown (September 19-20), the Confederates were victorious. Lee originally intended to resume the campaign after a brief stay in Virginia, but informed President Davis on September 25 that the condition of his army did not permit it.

Because of the Confederate withdrawal, it fell to the Union to treat the wounded and bury the dead of both sides. Around Sharpsburg, private homes, barns, and stables were converted into relief hospitals, where local residents also lent a hand. Burial parties of Union soldiers took over the task of laying out the dead. They worked until September 24. Because it had to be done in great haste, many of the mass graves were not dug very deep. Confederate soldiers passing Sharpsburg the following summer during the Gettysburg campaign observed numerous cadavers whose graves had been washed out by rain or dug up by hogs.

There is widespread agreement among historians that the Battle of Antietam was one of the turning points of the American Civil War, perhaps the most consequential. James M. McPherson summarizes the political and military consequences of the event thus:

Emancipation Proclamation and Congressional Elections

Lincoln had waited tensely for two months for a Union military success and thus an opportunity to issue the Emancipation Proclamation he had been quietly preparing. At a cabinet meeting on September 22, the president indicated that he regarded the outcome of the encounter at Sharpsburg as a divine sign to act, even though no crushing blow had been struck against the rebels. He announced the immediate publication of a preliminary declaration of emancipation. The Confederate states would then have until the end of the year to rejoin the Union, failing which the slaves in those states would be "forever free" as of January 1, 1863.

The Emancipation Proclamation was enthusiastically received by abolitionists such as Horace Greeley and Frederick Douglass. The former slave Douglass put his feelings into words, "We exult with joy that we may live to see this just decree." While some opponents of slavery criticized the fact that slaves in the border states of the Union were not affected, the majority recognized that Lincoln could only rule on "property of the enemy" ("enemy property"), not on the property of the people of Union states.

The Emancipation Proclamation met with almost unanimous rejection from the Democrats. Protest also arose in the border states, but this no longer impressed Lincoln. Resistance was strong in the ranks of the Army of the Potomac, especially among McClellan's followers, who accused the president of wanting to provoke a slave uprising in the South. McClellan considered this a nefarious strategy. Grumbling among his subordinates was so strong that McClellan had to issue a general order to counter rumors of an impending military coup. In it, he declared that there was only one antidote for political error, and that was to vote correctly at the polls-a clear attempt to sway public opinion in favor of the Democrats during the election campaign.

The Democrats' main issues in the campaign were the Emancipation Proclamation and the partial suspension (also promulgated by Lincoln after Antietam) of the Constitution's habeas corpus provisions. The partial suspension allowed the government to try radical opponents of new recruitments for the Union army, which had been enacted after the failure of McClellan's Peninsula campaign, before military tribunals. If there was agreement in opposition on these points, the dispute between "war Democrats" and "peace Democrats" strained the party's credibility. The Republicans exploited this in the election campaign and exaggerated the influence of the "peace Democrats" within the party. The elections, which took place between September and November, ultimately brought the Democrats gains in the House of Representatives and in individual states, but losses in the Senate. Republicans retained majorities in both houses of Congress-an important prerequisite for continuing Lincoln's war policy. The Battle of Antietam had swayed the mood of the electorate in favor of the Republicans. Before September 17, a Democratic majority in the new House of Representatives had generally been expected.

Reactions in Europe to Antietam and the Liberation of Slaves

The Battle of Antietam undermined the British government's plan to launch a mediation initiative with the prospect of subsequent recognition of the Confederacy. Prime Minister Palmerston wrote Foreign Secretary Russell in early October that they would wait until the war situation became clearer. A few weeks later he was more explicit. Southern defeats had clouded the prospect of successful mediation for the time being, he said, and he was now convinced "that we must remain merely in the spectator role until the war should have taken a more decisive turn."

France attempted to obtain the support of the British and Russian governments for a proposal of a six-month armistice in which the Union naval blockade of Confederate ports could be lifted and cotton exports resumed, but the governments of both countries rejected this. In a letter to Belgian King Leopold I, who also favored mediation, Palmerston explained in mid-November that the previously anticipated opportunity for such an undertaking had not materialized because of Confederate military setbacks.

The pro-Confederate section of the British public, led by The Times, condemned the Emancipation Proclamation as a cynical move by Lincoln, not based on outrage over slavery but a political maneuver designed to mislead foreign countries and incite slaves into bloody revolt. Pro-Unionist forces in Britain disagreed and acknowledged a serious move by Lincoln to abolish abhorred slavery. When the final text of the Emancipation Proclamation included a passage calling on freed slaves to renounce violence, support for the Union grew in Britain and other European countries. Lincoln's move had given moral legitimacy to the North's war aims. Recognition of the Confederacy was subsequently not seriously considered in Europe. Henry Adams, the son of the American ambassador, wrote home from London on January 23, 1863: "The Emancipation Proclamation has accomplished more for us here than all our previous victories and all our diplomacy."

Consequences for the perception and course of the war

Two days after the fighting ended, photographer Alexander Gardner began to record the horrific aftermath of the Battle of Antietam. During two stays in Sharpsburg, he took about 90 photographs of the village, battlefield, and living and dead soldiers, about 70 of them using the stereoscopic process, which was intended to give viewers a three-dimensional impression. The photographs were presented in October 1862 in a much-visited exhibition in the studio of Gardner's employer Mathew B. Brady in New York and subsequently reproduced as an attraction for stereo viewing devices. For technical reasons, newspapers and magazines could not yet reproduce photographs, but Harper's Weekly magazine used them as models for illustrations. Gardner's harrowing photographs of mutilated and bloated corpses, in particular, were a first in Civil War documentation. Although the dead depicted were almost invariably fallen Confederates (probably out of fear that images of dead Union soldiers might diminish support for the war in the North), public perception of the battlefield, which had been romanticized until then, changed as a result.

The Battle of Antietam, unlike most Civil War battles, was fought in only one day. Casualties were higher in six other encounters that took place in one location and extended over several days: Gettysburg, Chickamauga, Wilderness, Chancellorsville, Shiloh, and Stones River. With the exception of Shiloh, these encounters were after the Battle of Antietam. Nevertheless, in the memories of many participants who could make comparisons, Antietam was considered the worst battle of the Civil War. In particular, the battles for Cornfield, Bloody Lane, and Burnside Bridge came to epitomize the high toll of blood paid by soldiers on both sides in that conflict.

The Northern press celebrated the result of the battle, the Confederate withdrawal from Maryland, as a great Union success, the first real victory in the Eastern theater of war. Less than three weeks after Bull Run, the fortunes of the war had again undergone a sea change in public perception. After a series of failures and bloody defeats, the Union ranks at Antietam had not collapsed. Rather, the North had repulsed the Confederate invasion and seemingly seized the initiative. Although occasional criticism arose among journalists and the ranks of the Army of the Potomac for failing to crush Lee's army, the morale of Union soldiers improved noticeably.

Conversely, most in the Confederacy perceived the quick abandonment of the Maryland campaign as a defeat. Newspapers took pains to counter the pessimism, highlighting in particular Jackson's success at Harpers Ferry. This harmonized with the perception of numerous Confederate soldiers who stressed that they had not been defeated, but rather had so intimidated the Union army that it refrained from resuming fighting at Antietam. Individual participants in the Maryland campaign, however, acknowledged their disappointment that the Confederate attempt to go on the offensive had failed. General Lee himself was dissatisfied with the indiscipline displayed by many of his soldiers in Maryland, but did not make his reservations public. Public anger in the Southern states was drawn primarily by Marylanders who would not have lived up to the Southern expectations placed on them. The disappointment was soon repeated with regard to Kentucky, where Confederate incursions also tried in vain to drive the population into revolt against the Union.

In the weeks following the battle, the Army of the Potomac remained idle in its camps despite good weather and growing press displeasure that the advantage gained at Antietam had not been used. The Potomac was crossed only to recapture Harpers Ferry. Lincoln urged McClellan to attack Lee's army still standing in Northern Virginia, but was unsuccessful. On an extended visit to Sharpsburg in early October, the president renewed his call for a vigorous offensive against Lee's army in dialogue with McClellan and received evasive answers from the general.

Lincoln's displeasure with McClellan increased in the face of a raid, as spectacular as it was successful, conducted by Lee's cavalry between October 12 and 14. J.E.B. Stuart succeeded in advancing with 1800 men as far as Pennsylvania, taking extensive booty there and circling the entire Potomac Army in the ride without Union cavalry intervention. The Confederates lost only two men in the commando enterprise.

In several letters expressing his growing anger, the president in mid-October rejected McClellan's specious justifications for not pursuing Lee across the Potomac. An Oct. 13 letter from Lincoln stated, "Are you not over-cautious in supposing you cannot do something the enemy is constantly able to do?" Army Commander-in-Chief Halleck summed up his frustration with the inaction of the Army of the Potomac in these words, "There is a stalemate here beyond anything a man can conceive. It will take the lever of Archimedes to set this inert mass in motion."

It was not until October 26 that McClellan's army followed Lee across the Potomac, but it took nine days for this operation-compared to the few hours it had taken the Army of Northern Virginia after the Battle of Antietam. Lee was not impressed by the Union superiority and divided his weaker army as usual: Jackson's corps was to threaten McClellan's flank from the Shenandoah Valley, Longsstreet's corps to protect Richmond. The tentative advance of the Army of the Potomac in the face of this constellation finally convinced Lincoln of McClellan's unwillingness to attack the enemy.

On November 9, Lincoln deposed McClellan as commander-in-chief of the Army of the Potomac. He had waited until the congressional elections were over to make the move. McClellan was reluctantly replaced by Major General Burnside, who was to prove he was not up to the task at the Battle of Fredericksburg a month later. McClellan rejected calls from officers and troops to march on Washington to overthrow Lincoln and initially retired to private life. He never set foot on a battlefield again after that. He was unsuccessful as Lincoln's Democratic opponent in the 1864 presidential election.

In later writings justifying his strategic decisions with increasing stubbornness, McClellan reiterated his belief that he had personally saved the Union in September 1862 and won a great victory at Antietam. Most historians of the Civil War, meanwhile, emphasize not Union successes in Maryland (such as the fact that it would take Lee nine months before he could operate in Union territory again), but the opportunities missed by McClellan to defeat the Northern Virginia Army for good and thus shorten the war. A. Wilson Greene takes the dominant view when he writes: "Between September 13 and 18, 1862, George McClellan squandered the best opportunity ever to destroy the Confederacy's main field army. The nation paid the price for his failure during 31 additional months of Civil War."

39.4732-77.7447Coordinates: 39° 28′ 23.5″ N, 77° 44′ 40.9″ W

Sources

1. Battle of Antietam
2. Schlacht am Antietam
3. Stephen W. Sears: George B. McClellan. The Young Napoleon. Ticknor & Fields, New York 1988, ISBN 0-89919-264-5, S. 303.
4. Sears: McClellan. S. 303.
5. Im Original: „The bloodiest single day in American history“. Siehe: James M. McPherson: Crossroads of Freedom. Antietam. Oxford University Press, Oxford u. a. 2002, ISBN 0-19-513521-0, S. 11–12.
6. McPherson: Crossroads of Freedom. S. 11–12.
7. McPherson: Crossroads of Freedom. S. 11–12, 27–28.
8. ^ a b Eicher, p. 363, citează 75.500 soldați unioniști. Sears, p. 173, citează 75.000 de soldați unioniști, cu o forță efectivă de 71.500, cu 300 de tunuri; la p. 296, el afirmă că cei 12.401 combatanți unioniști pierduți erau 25% din cei care au intrat în acțiune și că McClellan a angajat „abia 50.000 de infanteriști și artileriști în luptă”; la p. 389, el citează forța confederată efectivă la „puțin peste 38.000”, inclusiv divizia lui Ambrose Powell Hill⁠(d), care a sosit după-amiaza. Priest, p. 343, citează 87.164 de oameni prezenți în Armata Potomacului, cu 53.632 angajați, și 30.646 angajați în Armata Virginiei de Nord. Luvaas și Nelson, p. 302, citează 87.100 de unioniști intrați în luptă, și 51.800 de confederați. Harsh, Sounding the Shallows, pp. 201–02, analizează istoriografia cifrelor, și arată că Ezra A. Carman (istoric militar care a influențat unele dintre aceste surse) folosea cifrele de efective „angajate”; cei 38.000 exclud brigăzile lui Pender și Field, circa jumătate din artilerie și forțele utilizate pentru a asigura obiectivele din spatele liniei.
9. ^ a b Uniunea: 12.410 total (2108 morți; 9549 răniți; 753 prizonieri/dispăruți); Confederația: 10.316 total (1546 morți; 7752 răniți; 1018 prizonieri/dispăruți) conform Sears, pp. 294–96; Cannan, p. 201. Pierderile sunt estimate deoarece cifrele cuprind victime nediferențiate la South Mountain⁠(d) și Shepherdstown⁠(d); Sears remarca că „nu este nicio îndoială că o bună parte din cei 1771 oameni dați dispăruți erau de fapt morți, îngropați fără a fi numărați în morminte nemarcate acolo unde au căzut.” McPherson, p. 129, dă următoarele estimări pentru pierderile Confederației: 1546–2700 morți, 7752–9024 răniți. El afirmă că peste 2000 de răniți din ambele tabere au murit din cauza rănilor. Priest, p. 343, consemnează 12.882 pierderi omenești pentru Uniune (2157 morti, 9716 răniți, 1009 dispăruți sau prizonieri) și 11.530 pentru Confederație (1754 morți, 8649 răniți, 1127 dispăruți sau prizonieri). Luvaas și Nelson, p. 302, citeează pierderile Uniunii la 12.469 (2010 morți, 9416 răniți, 1043 dispăruți sau prizonieri) și la 10.292 pe cele ale Confederației (1567 morți, 8725 răniți pentru perioada 14–20 septembrie, plus aproximativ 2000 de dispăruți sau prizonieri).
10. ^ McPherson 2002, p. 3.
11. ^ McPherson 2002, p. 100.
12. ^ a b Eicher 2001, p. 337.
13. ^ "Battle Detail - The Civil War (U.S. National Park Service)". Nps.gov. Retrieved February 15, 2022.
14. ^ McPherson 2002, p. 155
15. ^ "A Short Overview of the Battle of Antietam (U.S. National Park Service)". Nps.gov. Retrieved February 15, 2022.
16. ^ "Antietam Battle Facts and Summary | American Battlefield Trust". Battlefields.org. Retrieved February 10, 2022.
17. ^ a b Eicher, p. 363, cites 75,500 Union troops. Sears, p. 173, cites 75,000 Union troops, with an effective strength of 71,500, with 300 guns; on p. 296, he states that the 12,401 Union casualties were 25% of those who went into action and that McClellan committed "barely 50,000 infantry and artillerymen to the contest"; p. 389, he cites Confederate effective strength of "just over 38,000," including A.P. Hill's division, which arrived in the afternoon. Priest, p. 343, cites 87,164 men present in the Army of the Potomac, with 53,632 engaged, and 30,646 engaged in the Army of Northern Virginia. Luvaas and Nelson, p. 302, cite 87,100 Union engaged, 51,800 Confederate. Harsh, Sounding the Shallows, pp. 201–02, analyzes the historiography of the figures, and shows that Ezra A. Carman (a battlefield historian who influenced some of these sources) used "engaged" figures; the 38,000 excludes Pender's and Field's brigades, roughly half the artillery, and forces used to secure objectives behind the line.
18. McPherson, pág. 3.
19. Battle Sumary: Antietam, MD
20. Maryland era un estado esclavista aunque no se unió a la Confederación.
21. Sears, pp. 65-66; McPherson, pp. 88-95.