At dawn on September 17, 1862, Maj. General Joseph Hooker’s Union corps mounted a powerful assault on Robert E. Lee’s left flank that began the Battle of Antietam and the single bloodiest day in American military history.
Union attacks and Confederate counterattacks swept back and forth across Miller’s cornfield and the West Woods. Despite the Union’s superiority of numbers, Stonewall Jackson’s forces held their ground.
Meanwhile, towards the center of the battlefield, Union assaults would pierce the Confederate center after a terrible struggle for key defensive positions. Unfortunately for the Union army, this temporary advantage was not followed up with further advances.
Later in the day, Maj. General Ambrose Burnside’s troops forced their way across a bullet-strewn stone bridge over Antietam Creek and managed to imperil the Confederate right.
At a critical moment, a Confederate division arrived from Harpers Ferry and counterattacked, driving back Burnside and saving the day for the Army of Northern Virginia.
In spite of being outnumbered two-to-one, Lee committed his entire force at the Battle of Antietam. McClellan, however, sent in less than three-quarters of his Federal force. McClellan’s approach to the battle failed to take advantage of his superior numbers and allowed Lee to shift forces.
Even though he sustained crippling casualties, Lee continued to skirmish with McClellan on the 18th, although he did move his wounded south of the Potomac. McClellan, much to the dismay of Abraham Lincoln, did not vigorously pursue the wounded Confederate army.
While the Battle of Antietam is considered a draw from a military standpoint, Abraham Lincoln claimed victory for the Union. This hard-fought battle, which drove Lee’s forces from Antietam Bridge, Maryland, gave Lincoln the “victory” that he needed.
It enabled him to deliver the Emancipation Proclamation — the document that changed the course of the American Civil War.