Editing George B. McClellan (section)

====Battle of Antietam====
[[File:Antietam Overview.png|thumb|Overview of the Battle of Antietam]]
[[File:Lincoln and generals at Antietam.jpg|thumb|Lincoln with McClellan and staff after the Battle of Antietam. Notable figures (from left) are 5. [[Alexander S. Webb]], Chief of Staff, V Corps; 6. McClellan;. 8. [[Jonathan Letterman]]; 10. Lincoln; 11. [[Henry J. Hunt]]; 12. [[Fitz John Porter]]; 15. [[Andrew A. Humphreys]]; 16. Capt. [[George Armstrong Custer]]]]
The Battle of Antietam on September 17, 1862, was the single bloodiest day in American military history. The outnumbered Confederate forces fought desperately and well. Despite significant advantages in manpower, McClellan was unable to concentrate his forces effectively, which meant that Lee was able to shift his defenders to parry each of three Union thrusts, launched separately and sequentially against the Confederate left, center, and finally the right. McClellan was also unwilling, due to Porter's opinion, to employ his ample reserve forces to capitalize on localized successes. Historian James M. McPherson has pointed out that the two corps McClellan kept in reserve were in fact larger than Lee's entire force. The reason for McClellan's reluctance was that, as in previous battles, he was convinced he was outnumbered.<ref>McPherson, ''Crossroads'', pp. 129–130.</ref>

[[File:Lincoln and McClellan 1862-10-03.jpg|thumb|left|Lincoln in McClellan's tent after the Battle of Antietam]]
The battle was tactically inconclusive, with the Union suffering a higher overall number of casualties, although Lee technically was defeated because he withdrew first from the battlefield and retreated back to Virginia, and lost a larger percentage of his army than McClellan did. McClellan wired to Washington, "Our victory was complete. The enemy is driven back into Virginia." Yet there was obvious disappointment that McClellan had not crushed Lee, who was fighting with a smaller army with its back to the Potomac River. Although McClellan's subordinates can claim their share of responsibility for delays (such as Ambrose Burnside's misadventures at Burnside Bridge) and blunders ([[Edwin V. Sumner]]'s attack without reconnaissance), these were localized problems from which the full army could have recovered. As with the decisive battles in the Seven Days, McClellan's headquarters were too far to the rear to allow his personal control over the battle. He made no use of his cavalry forces for reconnaissance. He did not share his overall battle plans with his corps commanders, which prevented them from using initiative outside of their sectors. And he was far too willing to accept cautious advice about saving his reserves, such as when a significant breakthrough in the center of the Confederate line could have been exploited, but Fitz John Porter is said to have told McClellan, "Remember, General, I command the last reserve of the last Army of the Republic."<ref>Bailey, ''Bloodiest Day'', p. 141.</ref>

Despite being a tactical draw, Antietam is considered a [[Turning Point of the American Civil War|turning point]] of the war and a victory for the Union because it ended Lee's strategic campaign (his first invasion of the North) and it allowed President Lincoln to issue the Preliminary [[Emancipation Proclamation]] on September 22 and the Final Emancipation Proclamation on January 1, 1863. Although Lincoln had intended to issue the Preliminary Emancipation Proclamation earlier, Secretary of State [[William H. Seward]] advised him to wait until a Union victory to avoid the perception that it was issued out of desperation, and Lincoln accepted the advice. The Union victory and Lincoln's proclamation played a considerable role in dissuading the governments of [[Second French Empire|France]] and [[United Kingdom of Great Britain and Ireland|Britain]] from recognizing the Confederacy; some suspected they were planning to do so in the aftermath of another Union defeat.<ref>McPherson, ''Crossroads'', p. 155.</ref> McClellan had no prior knowledge that the plans for emancipation rested on his battle performance.

Because McClellan failed to pursue Lee aggressively after Antietam, Lincoln ordered that he be removed from command on November 5, 1862. Maj. Gen. Ambrose Burnside assumed command of the Army of the Potomac on November 9, 1862.<ref>Sears, ''Young Napoleon'', pp. 238–41.</ref> McClellan wrote to his wife, <blockquote>Those in whose judgment I rely tell me that I fought the battle splendidly and that it was a masterpiece of art.... I feel I have done all that can be asked in twice saving the country. ... I feel some little pride in having, with a beaten & demoralized army, defeated Lee so utterly.... Well, one of these days history will I trust do me justice.<ref>McPherson, ''Battle Cry'', p. 545.</ref></blockquote>