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