George B. McClellan was fired by Abraham Lincoln after the battle of Antietam. The battle ended with a Northern victory over the Confederate states lead by Robert E. Lee. Despite winning the battle, Lincoln fired McClellan for his refusal to pursue the retreating Confederate soldiers that would allow the Union to capture an immense number of soldiers and hurt the South's military. This has been a recurring theme before the battle with McClellan being too cautious to pursue soldiers in retreat, and lead to his firing.