United States Armies in the East > Department of Pennsylvania
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Commanded by Major General Robert Patterson (to July 25)
Major General John A. Dix
The Department of Pennsylvania merged with the Department of Maryland on July 25. General Order #46 honorably discharged Generals Patterson and Cadwallader at the end of their terms of service on July 27th, and almost all of the troops of Patterson’s army mustered out at that time. Thus General Dix and his troops from Maryland (which became known as Dix’s Division) became the Department of Pennsylvania.
| 1st Division | Brig. Gen. George Cadwallader | |
| 1st Brigade | Col. George H. Thomas | dissolved 7/25, regiments mustered out |
| 3rd Brigade | Brig. Gen. A. S. Williams | dissolved 7/22, regiments mustered out |
| 4th Brigade | Col. J. C. Longenecker | dissolved 7/21, regiments mustered out |
| 2nd Division | Maj. Gen. William H. Keim | |
| 2nd Brigade | Brig. Gen. G. C. Wynkoop | dissolved 7/23, regiments mustered out |
| 5th Brigade | Brig. Gen. J. S. Negley | dissolved 7/23, regiments mustered out |
| 6th Brigade | Col. J. J. Abercrombie | dissolved 7/21, regiments mustered out |
| 3rd Division | Major General C. P. Sandford | created 6/1 |
| 7th Brigade | Col. C. P. Stone | to Dept. Shenandoah, 3rd Brig. |
| 8th Brigade | Col. Schwartzwalder Col. D. Butterfield |
dissolved 7/25, regiments mustered out |
| Unattached | ||
| 11th Indiana Infantry Regiment | Colonel Lew Wallace | from Cumberland, Md. 7/8 to Indianapolis for muster out 7/29 |
| 1st United States Artillery, Battery E | from Fort Hamilton, New York 6/3 | |
| 1st United States Artillery, Battery H | from Fort Hamilton, New York 6/3 |
After July 25
| Dix’s Division | ||
| 1st Delaware Militia | Colonel Henry H. Lockwood | |
| 6th Massachusetts Infantry Regiment | Colonel Edward F. Jones | returned to Mass. to muster out 7/29 |
| 3rd New York Infantry Regiment | Lt. Colonel Samuel M. Alford | from Dept. of VA 7/30 |
| 4th New York Infantry Regiment | Colonel Alfred W. Taylor | from Dept. of VA 7/25 |
| 5th New York Infantry Regiment | Colonel C. Schwartzwaelder | from Dept. of VA 7/26 |
| 6th New York Militia Regiment | Colonel Joseph Pinckney | returned to New York 7/29 |
| 13th New York State Militia | Colonel Abel Smith | returned to New York 7/31 |
| 20th New York State Militia | Colonel George W. Pratt | returned to New York 7/31 |
| 1st Pennsylvania Reserves | Colonel R. Biddle Roberts | from Harrisburg 7/22 |
| 12th Pennsylvania Infantry Regiment | Colonel David Campbell | |
| 18th Pennsylvania Infantry Regiment | Colonel William D. Lewis | to Philadelphia 7/29 to muster out |
| 19th Pennsylvania Infantry Regiment | Colonel Peter Lyle | |
| 22nd Pennsylvania Infantry Regiment | Colonel Turner G. Morehead | |
| Cook’s Boston, Ma. Battery | ||
| 2nd United States Artillery, Battery I | at Fort McHenry |