The Union general criticized for his hesitance during the Battle of Antietam was George McClellan.

Known for his cautious approach to warfare, McClellan's reluctance to engage aggressively with Confederate forces during the battle on September 17, 1862, drew significant criticism from his superiors and the public. Despite having superior numbers, his hesitance limited the potential for a decisive victory against General Robert E. Lee's army. This cautious strategy ultimately contributed to the battle ending without a clear victor, despite the heavy casualties suffered on both sides, leading to ongoing debates about McClellan's effectiveness as a military leader.