Second Battle of Bull Run order of battle: Union

The following Union Army units and commanders fought in the Second Battle of Bull Run, also known as the Second Battle of Manassas, of the American Civil War. The Confederate order of battle is listed separately. Order of battle compiled from the army organization during the battle, the casualty returns and the reports.

Military rank

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

Other

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

Army of Virginia
MG John Pope

Chief of Staff: Col George D. Ruggles

Chief of Artillery: Cpt Alexander Piper

Chief of Cavalry: BG Washington L. Elliott (w)

Headquarters Escort:
 * 1st Ohio Cavalry, Companies A and C

I Corps
MG Franz Sigel (w)

Chief of Artillery: Cpt Ulric Dahlgren

Headquarters Escort:
 * 1st Indiana Cavalry, Companies I and K

III Corps
MG Irvin McDowell

Chief of Staff: Col Edmund Schriver

Chief of Artillery: Maj Davis Tillson

Headquarters Troops:
 * Maine Light Artillery, 3rd Battery (Pontonniers): Cpt James G. Swett
 * 13th Pennsylvania Reserves (1st Rifles), Companies C, G, H and I: Ltc Thomas L. Kane

Reserve Corps
BG Samuel D. Sturgis

Army of the Potomac
The following Corps from the Army of the Potomac were attached to the Army of Virginia.

III Corps
MG Samuel P. Heintzelman

V Corps
MG Fitz John Porter

Chief of Staff: Ltc Frederick T. Locke

IX Corps
MG Jesse L. Reno