United States Armies in the East > Department of Pennsylvania
< to April • May 1861 • to June >
Commanded by Major General Robert Patterson
| Unattached | ||
| 1st Pennsylvania Infantry Regiment | Colonel Samuel Yohe | to Dept. Annapolis 5/14 |
| 2nd Pennsylvania Infantry Regiment | Colonel Frederick S. Stumbaugh | at Camp Scott near York 4/21 |
| 3rd Pennsylvania Infantry Regiment | Colonel Francis P. Minier | at Camp Scott near York 4/20 |
| 4th Pennsylvania Infantry Regiment | Colonel John F. Hartranft | to Dept. Washington 5/8 |
| 5th Pennsylvania Infantry Regiment | Colonel R.P. McDowell | to Dept. Washington 5/27 |
| 6th Pennsylvania Infantry Regiment | Colonel James Nagle | to 1st Brigade (below) |
| 7th Pennsylvania Infantry Regiment | Colonel William I. Irwin | from Harrisburg 4/23 |
| 8th Pennsylvania Infantry Regiment | Colonel A.H. Emley | to Unattached, Chambersburg (below) |
| 9th Pennsylvania Infantry Regiment | Colonel Henry C. Longnecker | to Unattached, Chambersburg (below) |
| 10th Pennsylvania Infantry Regiment | Colonel Sullivan A. Meredith | from Harrisburg to Chambersburg 5/1 |
| 12th Pennsylvania Infantry Regiment | Colonel David Campbell | to Dept. Annapolis 5/25 |
| 13th Pennsylvania Infantry Regiment | Colonel Thomas A. Rowley | at York 4/26 |
| 14th Pennsylvania Infantry Regiment | Colonel John W. Johnston | mustered in at Harrisburg 4/30 |
| 17th Pennsylvania Infantry Regiment | Colonel Francis E. Patterson | Organized at Philadelphia 4/25 |
| 18th Pennsylvania Infantry Regiment | Colonel William D. Lewis, Jr. | to Dept. Annapolis 5/14 |
| 19th Pennsylvania Infantry Regiment | Colonel Peter Lyle | to Dept. Annapolis 5/10 |
| 20th Pennsylvania Infantry Regiment | Colonel Wiliam H. Gray | Mustered in at Philadelphia 4/30 |
| 21st Pennsylvania Infantry Regiment | Colonel John F. Ballier | to 1st Brigade (below) |
| 22nd Pennsylvania Infantry Regiment | Colonel Turner G. Morehead | to Dept. Annapolis 5/17 |
| 23rd Pennsylvania Infantry Regiment | Colonel Charles P. Dare | to 1st Brigade (below) |
| 1st Brigade | Colonel George Thomas | (at Chambersburg) |
| 6th Pennsylvania Infantry Regiment | Colonel James Nagle | from Unattached (above) |
| 21st Pennsylvania Infantry Regiment | Colonel John F. Ballier | from Unattached (above) |
| 23rd Pennsylvania Infantry Regiment | Colonel Charles P. Dare | from Perryville, Md. |
| Philadelphia City Troop Cavalry | Captain Thomas James | from Carlisle 5/31 |
| Unattached at Chambersburg | ||
| 8th Pennsylvania Infantry Regiment | Colonel A.H. Emley | from Harrisburg |
| 10th Pennsylvania Infantry Regiment | Colonel Sullivan A. Meredith | from Harrisburg 5/1 |