Federal Corps

Twelfth Army Corps

Commanding Officers on the Antietam Campaign:
  MGen Joseph K. F. Mansfield
  BGen Alpheus S. Williams

Members of Interest:
  Surg. Thomas Antisell, Medical Director
  Capt. Clarence H. Dyer, AAG
  Capt. James W. Forsyth, ADC

This Army Corps' Chain of Command:
  Army - Army of the Potomac

Units which make up this Army Corps:
  1st Division, 12th Corps
  2nd Division, 12th Corps
  Twelfth Corps Artillery
  1st Michigan Cavalry, Company L