Union
Army of Northeastern Virginia: Brigadier General Irvin McDowell

First Division: Brigadier General Daniel Tyler

First Brigade: Colonel Erasmus Keyes - 223
Second Brigade: Brigadier General Robert Schneck - 98
Third Brigade: Colonel William Sherman - 605
Fourth Brigade: Colonel Isreal Richardson - ---
TOTAL - 929

Second Division: Colonel David Hunter

First Brigade: Colonel Andrew Porter - 464
Second Brigade: Colonel Ambrose Burnside - 363
TOTAL - 829

Third Division: Colonel Samuel Heintzelman

First Brigade: Colonel William Franklin - 359
Second Brigade: Colonel Orlando Willcox - 432
Third Brigade: Colonel Oliver Howard - 225
TOTAL - 1, 016

Fifth Division: Colonel Dixon Miles

First Brigade: Colonel Louis Blenker - 118
Second Brigade: Colonel Thomas Davies - 3
TOTAL - 121

GRAND TOTAL - 2,896

Confederate
Army of the Potomac: Brigadier General P.G.T. Beauregard

First Brigade: Brigadier General M.L. Bonham - 76
Second Brigade: Brigadier General Richard S. Ewell - ---
Third Brigade: Brigadier General D.R. Jones - 75
Fourth Brigade: Brigadier General James Longstreet - 14
Fifth Brigade: Colonel P.St.G. Cooke - 104
Sixth Brigade: Colonel Jubal A. Early - 79
Seventh Brigade: Brigadier General Nathan G. Evans - 146
Holmes' Brigade: Brigadier General T.H. Holmes - ---
TOTAL - 638

Army of the Shenandoah: General Joseph E. Johnston

First Brigade: Brigadier General Thomas J. Jackson - 561
Second Brigade: Colonel Francis S. Bartow - 353
Third Brigade: Brigadier General Barnard Bee - 405
Fourth Brigade: Brigadier General E.K. Smith - 27
TOTAL - 1,357

Unattached: Hamptom Legion: Colonel Wade Hampton - 121

GRAND TOTAL - 1,226