During the battle of Antietam… George McClellan was concerned with prudence. He was managing his resources carefully that day, he would not allow his army to fail. His insistence on preventing the Army of the Potomac from being defeated cost it the chance at decisive victory. McClellan claimed in his report of the battle that his army was outnumbered and overcame great odds to achieve a minor tactical victory. A closer examination of the facts reveals McClellan was presented with three separate chances to strike a decisive blow against Lee between 6am- 1pm on September 17.
- A tactical reserve? McClellan kept the V & VI Corps of the army on the East side of the Antietam all day. The addition of one division from either Corps could have had a devastating impact on Lee’s army, especially his weakened center and southern wing.
- Foolish odds- Most historians now agree that McClellan withheld such a significant portion of his army because of fear. He feared being outnumbered (Lee was actually outnumbered 2-1). He feared a massive Confederate counterattack routing his forces. He feared defeat….
- Fighting blindly- Also massed in the Union rear was nearly all of McClellan’s cavalry force. The mounted wing was vital to Civil War armies for gathering intelligence. The troops sent against Lee were moving blindly through the country side with nearly no tactical guidance. Cavalry could have located fords on the Antietam easily.
- A guiding hand? McClellan never crossed the Antietam that day and had little trust in any of the commanders he sent into combat. The Union assaults lacked a firm hand to direct the many massed assaults. This allowed Lee (never far from the fighting) to coordinate his reinforcements. Union headquarters was nearly three miles from the fighting. McClellan’s lack of timely information and failure to grasp key tactical situations cost the Union a decisive victory.
- Hooker was badly wounded, Mansfield wounded mortally, and Sumner was incapacitated- yet the Army of the Potomac, led by junior grade officers, still pushed Lee to the brink. The victory could have been decisive.