< to June • July 1861
Redesignated Department of Maryland July 19
Merged into the Department of Pennsylvania July 25
Commanded by
Major General Nathaniel P. Banks (until July 19)
Major General John A. Dix
On July 19 the Department’s name was changed to the Department of Maryland. On July 25 it was merged into the Department of Pennsylvania, the former forces from Maryland becoming Dix’s Division.
| Infantry | ||
| 1st Delaware Infantry Regiment | Colonel Henry H. Lockwood | |
| 6th Massachusetts Infantry Regiment | Colonel Edward F. Jones | |
| 6th New York Militia Regiment | Colonel Joseph Pinckney | |
| 13th New York State Militia | Colonel Abel Smith | |
| 20th New York State Militia | Colonel George W. Pratt | |
| 1st Pennsylvania Reserves | Colonel R. Biddle Roberts | to Harrisburg 7/23 |
| 12th Pennsylvania Infantry Regiment | Colonel David Campbell | |
| 18th Pennsylvania Infantry Regiment | Colonel William D. Lewis | |
| 19th Pennsylvania Infantry Regiment | Colonel Peter Lyle | |
| 22nd Pennsylvania Infantry Regiment | Colonel Turner G. Morehead | |
| 4th Wisconsin Infantry Regiment | Colonal Halbert Paine | from Wisconsin 7/22 |
| Artillery | ||
| Cook’s Boston, Ma. Battery | ||
| 2nd United States Artillery, Battery I |