The 145th Pennsylvania Infantry was organized at Erie, Pennsylvania, and mustered in for a three-year enlistment on September 5, 1862, under the command of Colonel Hiram Loomis Brown.
The regiment was attached to 2nd Brigade, 1st Division, II Corps, Army of the Potomac, to October 1862.
1st Brigade, 1st Division, II Corps, to April 1863.
Moved to Harpers Ferry, Va., September 22, 1862, and duty there until October 29.
Advance up Loudoun Valley and movement to Falmouth, Va., October 29-November 17.
Demonstration north of the James at Deep Bottom July 27–29.
Mine Explosion, Petersburg, July 30 (reserve).
Demonstration on north side of the James at Deep Bottom August 13–20.
Dabney's Mills, Hatcher's Run, February 5–7, 1865.
Skirmishes on line of Hatcher's and Gravelly Runs March 29–30.
Hatcher's Run or Boydton Road March 31.