Third Division

Brigadier General John F. Reynolds

Transferred to the Army of the Potomac as the Third Division, First Army Corps, September 12, 1862

First Brigade

Bde. Gen. Truman Seymour

1st Pensylvania Reserves Regiment

Colonel Richard B. Roberts

Colonel William McCandless

Colonel Joseph W. Fisher

Colonel William Sinclair

Bde. Gen. George G. Meade

3rd Pensylvania Reserves Regiment

Colonel Horation G. Sickel (sick leave 9/1)

Lt. Colonel John C. Clark (after 9/1)

Colonel Albert L. McGilton

Colonel Henry C. Bolinger

Major Silas M. Baily

Colonel Hugh W. McNeill

Lt. Colonel Robert Andrson (9/1)

Colonel T. F. Gallagher (after 9/1)

Colonel Robert Anderson

Lt. Colonel Adoniram J. Warner

Colonel Thomas F. Gallagher (to 9/1)

Lt. Colonel Samuel Jackson

Captain Richard Gustin

Lieutenant John G. Simpson

Captain James H. Cooper

Lieutenant Frank P. Amsden

Captain Dunbar R. Ransom