< to July • August 1861
Commanded by Major General John A. Dix
Merged 8/24 into Department of the Potomac as Dix’s Division.
| Infantry | ||
| 1st Delaware Infantry Regiment | Colonel Henry H. Lockwood | |
| 20th Indiana Infantry Regiment | Colonel William L. Brown | from Lafayette, In. early Aug. |
| 21st Indiana Infantry Regiment | Colonel James W. McMillan | from Indiana early Aug. |
| 3rd New York Infantry Regiment | Lt. Colonel Samuel M. Alford | |
| 4th New York Infantry Regiment | Colonel Alfred W. Taylor | |
| 5th New York Infantry Regiment | Colonel C. Schwartzwaelder | |
| 1st Pennsylvania Reserves | Colonel R. Biddle Roberts | |
| 12th Pennsylvania Infantry Regiment | Colonel David Campbell | left for muster out 8/5 |
| 19th Pennsylvania Infantry Regiment | Colonel Peter Lyle | |
| 22nd Pennsylvania Infantry Regiment | Colonel Turner G. Morehead | left to muster out 8/7 |
| Artillery | ||
| Cook’s Boston, Massachusetts Battery | mustered out 8/2 | |
| 2nd United States Artillery, Battery I | at Fort McHenry |