At Antietam, there was a lot of stuff going on. For example, the Union had a ton of advantages. Some advantages were that the Union were fighting in the North. Another advantage was that they had twice as mAny soldiers so that meant that "The Union had more lives to spare than the Confederates." -Ms. Fielder. Also, it was the Union's lucky day because somebody in the Confederate Army dropped General Robert E. Lee's Battle plan and the Union had found it. The battle plan showed where the Confederate Army was going to head up to next and this meant that the Union could go and catch up to them. When the Union met up with the Confederates, a battle occured. It is said that this was the bloodiest single day of battle in the Civil War. Fortunatly for McClellan, the union General at the time, was fired but got reassigned because of his finding of the battle plan. He later got fired again after winning the battle because he didn't chase the Confederates after this. President Lincoln said that his general had "...a bad case of the slows."