June 1861 • to July >
Commanded by Brigadier General George Cadwallader
| 1st Brigade | Col. George H. Thomas (to 6/17) Col. Charles P. Dare |
|
| 6th Pennsylvania Infantry Regiment | Colonel James Nagle | |
| 21st Pennsylvania Infantry Regiment | Colonel John F. Ballier | |
| 23rd Pennsylvania Infantry Regiment | Colonel Charles P. Dare (^ 6/17) | |
| Philadelphia City Troop Cavalry | Captain Thomas James | |
| 2nd United States Cavalry (Cos. A,CF&K) | ||
| 4th U.S. Artillery (detatchment) | Captain Abner Doubleday | 1 8″ howitzer and 1 24-pounder |
| 3rd Brigade | Brig. Gen. Alpheus S. Williams | created 6/1 |
| 7th Pennsylvania Infantry Regiment | Colonel William I. Irwin | from unattached |
| 8th Pennsylvania Infantry Regiment | Colonel A.H. Emley | from unattached |
| 10th Pennsylvania Infantry Regiment | Colonel Sullivan A. Meredith | from unattached |
| 20th Pennsylvania Infantry Regiment | Colonel Wiliam H. Gray | from unattached |
| 4th Brigade | Colonel Dixon S. Miles (to 6/17) Colonel J. C. Longenecker |
created 6/1 |
| 9th Pennsylvania Infantry Regiment | Colonel Henry C. Longnecker | from Delaware 6/6 |
| 13th Pennsylvania Infantry Regiment | Colonel Thomas A. Rowley | from Harrisburg 6/4 |
| 16th Pennsylvania Infantry Regiment | Colonel Thomas A. Ziegle | from Harrisburg 6/3 |
| United States Regulars detachments | Major O.L. Sheppard | to Washington 6/17 |