Battle of Ball's Bluff order of battle: Union

The following Union Army units and commanders fought in the Battle of Ball's Bluff of the American Civil War, fought from October 20 to October 24, 1861, in Loudoun County, Virginia, also known as the Battle of Leesburg or the Battle of Harrison's Island. The Confederate order of battle is shown separately.

Military rank

 * MG = Major General
 * BG = Brigadier General
 * Col = Colonel
 * Ltc = Lieutenant Colonel
 * Maj = Major
 * Cpt = Captain
 * Lt = Lieutenant
 * Bvt = Brevet Rank

Other

 * w = wounded
 * mw = mortally wounded
 * k = killed

Army of the Potomac
MG George B. McClellan (not present)

Corps of Observation
BG Charles Pomeroy Stone