< to August • September 1862
Commanded by Major General John Pope (relieved September 3)
Discontinued and merged into the Army of the Potomac as the 11th Corps on September 12, 1862
| First Corps | Major General Franz Siegel | |
| First Division | Brigadier General Julius Stahel | to Army of the Potomac, 11th Corps |
| Second Division | Brigadier General Adolf Von Steinwehr | |
| Third Division | Brigadier General Carl Schurz | |
| Milroy’s Independent Brigade | Brigadier General R. Milroy | |
| Cavalry Brigade | Colonel John Beardsley | |
| Second Corps | Major General Nathaniel P. Banks | |
| First Division | Brigadier General Alpheus Williams (to 9/4) Brigadier General Samuel W. Crawford |
to Army of the Potomac, 12th Corps |
| Second Division | Brigadier General George S. Greene | |
| Cavalry Brigade | Brigadier General John Buford | |
| Third Corps | Major General Irvin McDowell (to 9/5) Brigadier General J. B. Ricketts (9/5 – 9/6) Major General Joseph Hooker |
|
| First Division | Brigadier General Abner Doubleday | to Army of the Potomac, 1st Corps |
| Second Division | Brigadier General John B. Ricketts | |
| Third Division | Brigadier General John F. Reynolds | |