After being unable to stop the unrelenting Federal advance against his rear lines at the Battle of South Mountain while the rest of his army is separated throughout Maryland and Virginia, Confederate General Robert E Lee makes the difficult decision to end his campaign before he loses the rest of his army. To ensure he can safely cross back into Virginia, Lee orders his army to rally at the small little town of Sharpsburg and then proceed across the Potomac together. However, Union Major General George B McClellan stalls his advance in front of Sharpsburg, allowing the Confederates to rally their forces unimpeded. While in Sharpsburg, Lee receives wonderful news that his subordinate Major General Thomas Jackson has captured the strategic town of Harpers Ferry and its garrison. With McClellan not showing any signs of aggression and Jackson freed up from his siege, Lee realizes a chance of retaking the initiative in Maryland and holds his forces north of the river. Hoping to win a long elusive battle on northern soil. After two days of waiting, McClellan makes his move, on September 17, 1862, these two colossal figures will once again come to blows. If Lee is successful here, along the meandering creek of Antietam, he might be able to swing the war solidly in his favor...