Battle of Antietam

The Battle of Antietam was an American Civil War (1861–65) battle that happened along Antietam Creek near Sharpsburg, Maryland , on September 17, 1862. Confederate general Robert E. Lee (1807–1870) had undertaken an invasion of the North. He hoped to gain the loyalty of people in Maryland and boost the strength of the Confederate States of America (or Southern) cause in the border state. He also hoped to lure federal troops away from Virginia to relieve the area temporarily from the ravages of war. Lee's advance north was a great threat to the Union and its capital, Washington, D.C. Union general George B. McClellan (1826–1885) learned of some of Lee's plans and pursued the Confederates.

On the night of September 13, Lee heard that McClellan had learned of his plans. Rather than retreating in the face of an army twice as big as his, Lee decided to face the federal troops, so he paused in Sharpsburg. McClellan advanced on the evening of September 16 and carefully moved his men into position.

The battle that ensued the following day marked the bloodiest single day of the war. McClellan launched a series of uncoordinated attacks on three sectors of Lee's forces. The Confederate forces were pushed back but avoided complete disaster with the arrival of troops from Harper's Ferry, Virginia (now part of West Virginia ) under Confederate general A. P. Hill (1825–1865). Fighting only paused with the dark of night.

On the following day, Lee stood fast, but McClellan did not renew his attack. Lee recognized that a renewed attack was futile and so ordered a retreat to Virginia. His troops withdrew across the Potomac River on September 19. McClellan's forces were badly crippled as well, so he decided not to pursue Lee's forces.

The battle's dead, wounded, and missing totaled over twelve thousand for each side. The battle, however, is remembered for more than its casualties. Many historians regard it as the turning point of the war. The stunning victory by the Union provided U.S. president Abraham Lincoln (1809–1865; served 1861–65) with military progress for which he had been waiting.

Lincoln followed the victory with an announcement of his Emancipation Proclamation . The proclamation declared freedom for slaves in the rebelling states. It changed the war from a political crusade to preserve the Union into a crusade to free the slaves and end slavery . The addition of a moral element to the North's cause impassioned supporters, made it a difficult war to abandon, and swung foreign support to the Union's side. All of this contributed to the eventual Union victory.