From the Peninsula to Maryland: Hill's role in the summer of 1862
After helping to stop McClellan's push toward Richmond during the Peninsula Campaign D. H. Hill's division remained in the Richmond area, and did not move north with the rest of the Army of Northern Virginia in the Northern Virginia Campaign of August 1862.
He was, however, moved north to rejoin the rest of the army before Lee launched an invasion into Maryland in September 1862, hoping to shift the war's focus away from Virginia and beat Union forces on their own soil.
Hill's reputation was tarnished when he received the blame for the lost copy of Special Orders 191, which had fallen into the hands of Union commander George McClellan. This order detailed the movements of Lee's army, and revealed that Lee had split his force into five separate groups. Hill's division was ordered to "Cross South Mountain west of Middletown and go into camp at Boonsboro." Hill's movement in response to these orders placed his division as the primary barrier to impede the advance of the Army of the Potomac, which was marching to cut off the disparate elements of Lee's command before they could rejoin together. Hill's men performed admirably at the Battle of South Mountain on September 14-15, buying enough time for the full strength of Lee's army to arrive on the field of Antietam on September 17.
During the fighting at Antietam Hill's division again saw fierce action, this time in the sunken road ("Bloody Lane"). Despite having three horses shot out from under him, Hill rallied detached forces from several different brigades to successfully hold the line against repeated Union attacks and prevent a Union breakthrough for nearly four hours, from 9:30 a.m. to 1 p.m.
Even when the Federals were finally able to overwhelm Hill's position, successfully driving his men from the sunken road and piercing the center of the Confederate line, sheer exhaustion and confusion kept them from following up this success with any additional attack on this part of the battlefield.