For the North, the fight along Antietam Creek became known as the Battle of Antietam. In the South, it became known as the Battle of Sharpsburg. Of the nearly 70,000 Federal troops actually engaged in the battle, nearly 13,000 were killed, wounded, or missing; the approximately 35,000 Confederates engaged lost almost as many.
Writing to his wife, McClellan said, "Those in whose judgment I rely tell me that I fought the battle splendidly and that is was a masterpiece of art. "In truth, however, McClellan missed a series of opportunities. By failing to commit his forces to battle on 15 and 16 September, McClellan squandered a chance to exploit his numerical superiority. On 17 September McClellan's piecemeal commitment of only a portion of his command during the battle-"in driblets," as General Sumner later described it failed to deliver a knockout blow to destroy the Army of Northern Virginia. McClellan's decision not to renew the battle on 18 September, with the same if not greater opportunity of success as the previous day, as well as his failure to energetically pursue the Confederate army on 19 September, allowed Lee to withdraw to the safety of the Virginia shore.
Lee, like McClellan, generally believed that the role of an army commander was to bring his army to the battlefield and allow his subordinates to handle the tactical details. But the desperate situation on 17 September forced Lee to become actively involved in the battle, despite injuries to both his hands. He spent most of the day on the heights in the area of the present day National Cemetery, where he watched the progress of the battle and personally dispatched various units to endangered portions of the field. He sent the commands of Walker, McLaws, and G. T. Anderson just in time to halt Sedgwick's advance on the Confederate left flank; rushed R. H. Anderson to support D. H. Hill's defense of the Confederate center; and, when A. P. Hill's division began arriving at Sharpsburg in the afternoon, hurried Hill's command to save the Confederate right flank.
Although the Confederates had been forced out of Maryland, Lee's campaign had been a partial success. Jackson's capture of Harper's Ferry provided the Confederates with a large amount of supplies, including clothing, shoes, thousands of small arms and ammunition, and over seventy pieces of artillery. In addition, another major Federal offensive in Virginia had been delayed, albeit only briefly. In mid-December Burnside, now commanding The Army of the Potomac, attempted to interpose his command between Lee and Richmond. The maneuver culminated in a Union defeat at the Battle of Fredericksburg.
Although Antietam was not the decisive Union victory for which Lincoln had hoped, it did give the president an opportunity to strike at the Confederacy politically, psychologically, and economically. On 22 September Lincoln issued the preliminary Emancipation Proclamation, declaring that the Federal government would after 1 January 1863 consider slaves in any state in rebellion against the Federal government to be free. The proclamation had no immediate effect behind Confederate lines, nor did it free any slaves in states still in the Union. Nevertheless, Lincoln's proclamation would be the Federal government's first official step toward the abolition of human slavery.
Shortly after the battle, McClellan wrote that Confederate dreams of invading Pennsylvania had dissipated forever. During the coming months, however, Lee would wait for another opportunity to cross his army north of the Potomac. The summer of 1863 would find the Army of Northern Virginia and the Army of the Potomac, the latter commanded by the recently promoted Maj. Gen. George Meade, confronting each other at the small Pennsylvania town of Gettysburg.
Antietam Battle Details
The Gleam Of Bayonets: The Battle Of Antietam And Robert E. Lee's Maryland Campaign, September, 1862
Antietam turned the tide of the Civil War in favor of the North and delivered the first major defeat to Robert E. Lee's Confederate army. The gentleness and patience of Lincoln, the vacillations of McClellan, and the grandeur of Lee—all unfold before the reader