 Lee had fewer than 40,000 men on the field at Antietam, the smallest his army would be until the Appomattox Campaign, and the battle was largely fought on autopilot with minimal involvement by the senior officers in the army.During the Fredericksburg Campaign, Longstreet had the divisions of Anderson, Hood, McLaws, Ransom, and George Pickett, who had just returned to action after months of convalescence from a wound sustained at the Battle of Gaines's Mill.Jackson had the divisions of D.H. Hill, A.P.