What happened at the battle of antietam? who won?

General George McClellan was fired not long after the battle, despite the victory. President Lincoln was unhappy that McClellan let the overmatched Confederates retreat back to Virginia rather than destroying the army completely. Union troops marched to Antietam from Washington, D.C. to stop Lee's Army of the Potomac.

Considered one of the bloodiest wars ever. the battle lasted 12 hours. it was declared union victory. hope this helps

Ithink that it is d