The Conflict at Antientam: Potomac and Maryland

When the morning of the 18th dawned, both parties seemed willing not to renew the strife. Lee was really in a sad plight, for he could not easily call to his aid any re-inforcements; his supplies were nearly exhausted, and his army was terribly shattered and disorganized. A careful estimate has made his losses at that time, since he commenced the invasion of Maryland, a fortnight before, nearly thirty thousand men. McClellan's army was also greatly shattered; but on the morning after the battle he was joined by fourteen thousand fresh troops under Couch and Humphreys. It is certain now that with these, and the effective remains of his army, he might easily have captured or ruined Lee's army that day. But there were grave considerations to be heeded. McClellan afterwards said, "Virginia was lost, Washington menaced, Maryland invaded: the national cause could afford no risk of defeat." He therefore hesitated, and finally, in opposition to the advice of Franklin and others, he deferred a renewal of the battle until the next morning. When that morning dawned, and he sent his cavalry to reconnoitre, the national army had no foe to fight, for Lee, with his shattered legions, had recrossed the Potomac under cover of darkness, and was on the soil of his native Virginia, with eight batteries under Pendleton on the river-bluffs, menacing pursuers.

On the 20th a portion of the Union army crossed the river in pursuit, and was repulsed with heavy loss. Lee retreated down the Shenanaoah Valley, while McClellan, after considerable delay in reorganizing and refitting his forces, marched his army to Warrenton. His slowness gave such dissatisfaction to the authorities at Washington that on November 7 he was relieved from duty, and replaced by General Burnside in command of the Army of the Potomac.