Mr. Byrd, Robin Young has written a book about Sullivan Ballou. I only recall the first part of the title, "For Love and Liberty...". I can get the full title early next week if you require. Ms. Young makes a very good case that Ballou's body was exhumed and descrated by members of the 21st Georgia.
Ballou died and was buried at Sudly Church, which had been turned into a field hospital after the Battle of Manassas.The 21st Ga. wintered within 2 miles of the Church and some of the soldiers were hospitalized there for illness. This I can conferm in my own research. Ballou's shull and perhaps some of his bones were stolen some time in Jan. 1862.
All the records and accounts I have found, including Robin Young's, indicate the 21st Georgia was not in the first Battle of Manasses. Every thing indicates at the time of the battle the Regiment was organizing and training in Richmond, Va. Note: the unit could have also been listed as Mercer's 4th Battalion.
Perhaps someone else could shine more light on where the Regiment was. Regards R. Cofer