Antietam was the bloodiest single day in American history. On September 17, 1862, the Army of the Potomac and the Army of Northern Virginia met along Antietam Creek near Sharpsburg, Maryland. By nightfall, approximately 23,000 men were dead, wounded, or missing. The battle was tactically inconclusive - neither side could claim clear victory - but strategically it changed everything. Lee's first invasion of the North was stopped; he retreated to Virginia. Lincoln, who had been waiting for a victory to issue the Emancipation Proclamation, now had one. Five days later, he announced that slaves in rebel states would be free as of January 1, 1863. Antietam transformed the Civil War from a conflict to preserve the Union into a war to end slavery. The Sunken Road, the Cornfield, and Burnside's Bridge became names Americans would never forget.
Robert E. Lee invaded Maryland in September 1862, hoping to win a victory on Northern soil that would bring European recognition of the Confederacy and perhaps peace negotiations. His army was exhausted and understrength. George McClellan's Army of the Potomac pursued cautiously, then received an extraordinary gift: a lost copy of Lee's orders wrapped around three cigars, revealing the Confederate army was divided. McClellan had a chance to destroy Lee piecemeal. He moved too slowly. Lee concentrated his forces near Sharpsburg, his back to the Potomac River. On September 17, McClellan attacked.
The battle unfolded in three phases across the Maryland landscape. At dawn, Hooker's corps attacked through the North Woods and into the Cornfield, where fighting was so fierce that the corn was cut down 'as by a scythe.' Neither side could hold the field; it changed hands fifteen times. To the south, the Sunken Road - which became 'Bloody Lane' - saw horrific fighting as Confederate defenders held a natural trench until they were flanked and the lane filled with bodies. In the afternoon, Burnside's corps finally crossed the bridge that bears his name after hours of delay, only to be stopped by A.P. Hill's division arriving from Harpers Ferry.
The numbers are staggering: approximately 12,400 Union casualties and 10,300 Confederate. In twelve hours, more Americans fell than in all previous American wars combined. The dead lay in windows along Bloody Lane, in piles at the Cornfield, scattered across Miller's farm. Civilians spent days burying the dead, photographing the horror. Alexander Gardner's photographs of Antietam's dead, displayed in New York, showed Americans what war really looked like. 'Let him who wishes to know what war is look at this series of illustrations,' wrote the New York Times.
Lincoln had drafted the Emancipation Proclamation in July but waited for a military success to announce it - issuing it after defeats would look like desperation. Antietam, though not the decisive victory he wanted, was enough. On September 22, Lincoln announced that slaves in rebel states would be free as of January 1, 1863. The proclamation changed the war's character. Union soldiers were now fighting to end slavery. European powers, especially Britain, could not recognize the Confederacy without appearing to support slavery. The war that began to save the Union became a war for freedom.
Antietam National Battlefield is located near Sharpsburg, Maryland, about 70 miles northwest of Washington, D.C. The visitor center provides orientation and a film. An 8.5-mile driving tour follows the battle's progression from the North Woods through the Cornfield, Bloody Lane, and Burnside's Bridge. Walking trails explore key areas in depth. The Sunken Road and Burnside's Bridge are particularly evocative. The park includes the Antietam National Cemetery, where Union dead from multiple battles are buried. The battlefield is well-preserved and often quiet - a profound contrast to the carnage of 1862. Washington Dulles (IAD) and Baltimore (BWI) airports are equidistant.
Located at 39.47°N, 77.74°W in the rolling farmland of western Maryland, along Antietam Creek near Sharpsburg. From altitude, the battlefield appears as pastoral farmland divided by woodlots and fence lines. The creek meanders through the eastern portion; Burnside's Bridge crosses it. The National Cemetery is visible as a formal green space. The Potomac River flows to the west. The terrain that shaped the battle - the Cornfield, the Sunken Road, Burnside's Bridge - is preserved as it was in 1862, surrounded by modern development pressing at the boundaries.