Who won the Battle of Antietam?
The Battle of Antietam, fought on 17 September 1862, was a strategic Union victory, though tactically it was inconclusive. With about 22,700 men killed, wounded or missing, it remains the bloodiest single day in American history and gave Abraham Lincoln the moment to issue the Emancipation Proclamation.1
Dawn on 17 September 1862 broke gray and misty over the Maryland farmland around Sharpsburg, and within hours it would become the deadliest single day the United States had ever known. By nightfall an estimated 22,000 to 23,000 men lay killed, wounded or missing along the banks of a quiet stream called Antietam Creek. Two great armies, General Robert E. Lee's Army of Northern Virginia and General George B. McClellan's Army of the Potomac, had thrown themselves at one another across cornfields, a sunken country lane and a narrow stone bridge, and when the guns fell silent the ground itself seemed changed forever.2
Part of The greatest battles of the Civil War · Before: The Battle of Shiloh · Next: The Battle of Perryville
Lee carries the war north
Flush with victory after the Second Battle of Bull Run, Lee gambled on a bold stroke: he would carry the war out of ravaged Virginia and onto Northern soil for the first time. An invasion of Maryland might draw the border state to the Confederate cause, feed his hungry army from Union fields, and perhaps convince Britain and France to recognize the young Confederacy. According to the American Battlefield Trust, Lee also hoped that success on Union ground could sway the coming Congressional elections in the North. Lincoln, for his part, needed a victory just as badly, because he had decided to wait for one before announcing a policy of emancipation.3
What was Special Order 191, the “Lost Order”?
Special Order 191 was Lee's plan for the Maryland campaign, issued on 9 September 1862. It split his army into several parts so that one wing could capture the Union garrison at Harpers Ferry. On 13 September soldiers of the 27th Indiana found a copy near Frederick, Maryland, wrapped around three cigars, and it reached McClellan the same day.4
The orders were drafted by Lee's chief of staff, Robert H. Chilton. Three columns under Thomas J. “Stonewall” Jackson were to surround Harpers Ferry while James Longstreet's command guarded the mountain passes, a gamble that broke the rule against dividing an army in the face of a stronger enemy. The lost copy was a spare addressed to General D. H. Hill, who always insisted he had never received it; the American Battlefield Trust concludes that who lost it, and how, can no longer be established. Samuel Pittman, adjutant of the Union division, recognized Chilton's handwriting because before the war, as a bank teller, he had handled Chilton's checks, which helped convince the Union command that the document was genuine.5
McClellan now knew that his opponent's army was scattered, though he would move too slowly to exploit it fully. On 14 September his troops fought their way through the passes of South Mountain. The next day, however, the Union garrison at Harpers Ferry, some 13,000 men, surrendered to Jackson, in the Trust's words “the largest surrender of American troops until World War II”. Rather than retreat to Virginia, Lee chose to make a stand on the high ground west of Antietam Creek, near the town of Sharpsburg, and called his scattered divisions together there.6
How many soldiers fought at Antietam?
McClellan's Army of the Potomac numbered about 87,000 men. Estimates for Lee's Army of Northern Virginia run from about 41,000, the National Park Service figure, to 45,000 in the American Battlefield Trust's count, so roughly 130,000 soldiers were present in all. Lee was outnumbered about two to one.7
The Park Service notes that straggling on the march had cut Lee's army from about 55,000 to 41,000 men before the battle. The imbalance mattered less than it might have, because the two generals used their armies very differently. Lee committed his entire force, shifting brigades from one threatened point to the next, while McClellan committed fewer than three quarters of his men and left a large reserve that never went into action.8
His plan was to strike Lee's left, then his right, and to attack the center once either flank gave way; in practice the Union assaults came one at a time, from north to south, and Lee met each of them in turn. The generals on both sides are profiled in our guide to the commanders of the American Civil War.9
What happened in the Cornfield at Antietam?
The Cornfield was D. R. Miller's farm field at the northern end of the battlefield, where the fighting began at dawn on 17 September. For about three hours Union and Confederate troops attacked and counterattacked across it, and the field changed hands at least six times. By 9:30 a.m. thousands of men lay dead or wounded there.10
Joseph Hooker's Union I Corps opened the assault, followed by Joseph Mansfield's XII Corps, against Confederates under Stonewall Jackson. Hooker later recalled that “every stalk of corn in the northern and greater part of the field was cut as closely as could have been done with a knife, and the slain lay in rows precisely as they had stood in their ranks a few moments before”.11
Mansfield was mortally wounded leading his corps toward the field and died the next day. The National Park Service estimates that about 27,000 men fought in the Cornfield between 5:30 and 9:30 in the morning, and that some 8,200 of them became casualties. Despite the Union advantage in numbers, Jackson's men held their ground near the Dunker Church.12
Around 9 a.m. a fresh Union attack by Edwin Sumner's II Corps pushed into the West Woods beyond the church. A Confederate counterattack struck its flank, and according to the Park Service, 2,200 of the 5,300 Union soldiers who entered the woods were killed or wounded in about twenty minutes. By 10 a.m. the fighting on the northern end of the field had died down. Close to 10,000 men had been killed or wounded there in four hours.13
Why is it called the Bloody Lane?
The Bloody Lane is a sunken farm road in the center of the battlefield. Worn below the level of the fields by years of wagon traffic, it gave the Confederates a ready-made trench. After more than three hours of fighting there, about 5,500 men lay dead or wounded in and around it, and the name has stuck ever since.14
About 2,200 Confederates of D. H. Hill's division, later reinforced, lined the road behind piled fence rails. From about 9:30 a.m. the Union divisions of William French and Israel Richardson, nearly 10,000 men in all, came at them across open ground. The Irish Brigade under Thomas F. Meagher led Richardson's assault and, by the American Battlefield Trust's count, suffered 540 casualties.15
Shortly after noon Union troops worked their way onto the flank of the lane and caught its defenders in a crossfire, and the Confederate center fell back toward the Piper farm. The Confederate brigade commander George B. Anderson and the Union division commander Richardson were both mortally wounded. Yet the attackers had lost too many men to press on, and McClellan ordered them to hold their ground rather than send in his reserve to finish the break in Lee's line.16
What happened at Burnside's Bridge?
Burnside's Bridge is the stone bridge over Antietam Creek at the southern end of the battlefield. About 500 Confederate riflemen, most of them Georgians, held it against Ambrose Burnside's Union IX Corps for three to four hours, depending on the account, before Union troops finally stormed across at about 1 p.m.17
Burnside's orders to advance were written at 9 a.m. and did not reach him until 10 a.m., according to the American Battlefield Trust. Two uncoordinated attempts on the bridge failed while a division under Isaac Rodman searched downstream for another crossing. At last the 51st Pennsylvania and the 51st New York charged over the span. It then took Burnside about two hours to bring his corps across and form it for the next attack.18
In mid-afternoon some 8,000 Union soldiers advanced over the rolling ground toward Sharpsburg and the road to Boteler's Ford, Lee's line of retreat across the Potomac. Just as the Confederate right began to give way, A. P. Hill's division arrived from Harpers Ferry, after a march of some 15 to 17 miles that day, and struck the exposed Union left flank. The 16th Connecticut, a regiment only about two weeks old, took the worst of the blow. Rodman was mortally wounded, and the Union line fell back toward the creek. As darkness fell the two exhausted armies still faced each other, neither having landed a decisive blow. Tactically, the day had ended in a bloody stalemate.19
How long did the Battle of Antietam last?
The Battle of Antietam lasted a single day. The fighting began at dawn on 17 September 1862 in the Cornfield and ended around sunset after A. P. Hill's counterattack on the southern flank, about twelve hours of combat in all. The armies faced each other through 18 September, and Lee withdrew that night.20
The battle moved across the field from north to south in three phases: the morning struggle for the Cornfield and the East and West Woods, the late morning and midday fight for the Sunken Road, and the afternoon battle for the lower bridge and the ridges south of Sharpsburg.21
How many died at Antietam?
About 3,650 soldiers were killed outright at Antietam, and the total of killed, wounded and missing or captured came to about 22,700, according to both the National Park Service and the American Battlefield Trust. Other Park Service pages give 23,000 or more. Many of the wounded died in the days and weeks that followed.22
| Side | Killed | Wounded | Missing or captured | Total |
|---|---|---|---|---|
| Union (ABT) | 2,108 | 9,540 | 753 | 12,401 |
| Confederate (ABT) | 1,546 | 7,752 | 1,018 | 10,316 |
| Both armies (ABT) | 3,654 | 17,292 | 1,771 | 22,717 |
| Both armies (NPS, rounded) | 3,650 | 17,300 | 1,770 | 22,720 |
ABT: American Battlefield Trust. NPS: National Park Service. A casualty is any soldier killed, wounded, or missing or captured.
Civil War casualty figures combine three categories, the dead, the wounded and the missing or captured, so the famous total is not a death toll. The Park Service draws its numbers from the Official Records of the war and the Antietam Battlefield Board, and stresses that exact figures could never be compiled.23
Britannica gives the same split as the Trust, 12,401 Union and 10,316 Confederate casualties. The park's own pages are not uniform: its history of the National Cemetery speaks of more than 23,110 killed, wounded or missing and about 4,000 killed, while its battle overview rounds the total to 23,000. Across the war as a whole, the Park Service estimates, about one wounded soldier in seven died of his wounds. At Antietam six generals, three on each side, were killed or mortally wounded.24
Antietam was not the costliest battle of the war. Gettysburg, fought about nine months later, produced more than 51,000 casualties, but over three days. What sets Antietam apart is the concentration of loss into a single day, the record that both the American Battlefield Trust and Britannica assign to it. For comparison with other great slaughters, see our list of the deadliest battles in history.25
An inconclusive field, a turning point
Lee held his ground through the following day, daring McClellan to renew the attack, but the Union commander, ever overcautious, did not. That night Lee withdrew his battered army back across the Potomac into Virginia. A cautious Union pursuit over the river was turned back at Shepherdstown on 19 and 20 September. Because Lee abandoned his invasion and retreated, the North could rightly claim Antietam as a strategic victory, even though McClellan failed to destroy the Confederate army when he had the chance.26
Lincoln lost patience with his general. He visited the army at Antietam in early October to urge an advance, and when McClellan finally moved into Virginia, he moved slowly. On 7 November 1862 Lincoln relieved him of command and gave the Army of the Potomac to Burnside. The battle's larger consequences, though, reached far beyond the army, and they explain why Antietam ranks among the greatest battles in American history.27
How did Antietam lead to the Emancipation Proclamation?
Lincoln had drafted an emancipation proclamation in July 1862 but, on the advice of Secretary of State William Seward, waited for a Union victory so that it would not look like an act of desperation. Antietam gave him that victory. On 22 September 1862, five days after the battle, he issued the preliminary Emancipation Proclamation.28
The preliminary proclamation warned that on 1 January 1863 enslaved people in any state or part of a state still in rebellion would be “then, thenceforward, and forever free”. When that day came, Lincoln issued the final proclamation, framed as a war measure under his powers as commander in chief. It did not apply to the loyal border states, so it freed no one in Maryland, where the battle had been fought. Slavery was abolished throughout the United States only by the Thirteenth Amendment, ratified in December 1865.29
The proclamation also changed the war abroad. Once the end of slavery became a Union war aim, it was much harder for Britain or France, where many people opposed slavery, to back the Confederacy. In the end, the American Battlefield Trust notes, both powers declined to form an alliance with the South.30
Where was the Battle of Antietam fought and what is there today?
The battle was fought along Antietam Creek, about a mile east of Sharpsburg in Washington County, Maryland, close to the Potomac River. Much of the field is now Antietam National Battlefield, run by the National Park Service, and both the Park Service and the American Battlefield Trust describe it as one of the best preserved Civil War battlefields.31
The battle is also known as Sharpsburg, after the town. According to the park's own history, preservation began with a few lines added to a large spending bill that set aside money to survey and mark the lines of battle; it was signed into law on 30 August 1890. Rather than buy whole farms, the War Department's Antietam Battlefield Board bought small plots for roads and placed hundreds of cast-iron tablets explaining the troop movements, while Ezra Carman, who had fought there as colonel of the 13th New Jersey, spent some twenty years mapping the battle. The War Department handed the battlefield to the National Park Service on 10 August 1933.32
Visitors today can follow a self-guided tour road 8½ miles long with 10 stops, past the Dunker Church, the Cornfield, Bloody Lane and Burnside Bridge. Antietam National Cemetery, the Park Service records, holds 4,776 Union dead from Antietam and other actions in Maryland, 1,836 of them unknown, and was dedicated on 17 September 1867, the fifth anniversary of the battle. The Confederate dead were reburied in cemeteries at Hagerstown, Frederick and Shepherdstown.33
Test yourself on the war with the American battles quiz, or see if you can call the result in Who Won the Battle?
