Thomas Harper entered service from Berks Co, PA 1 Mar 1777 under Capt. John Reese of the 3rd PA Regiment; that the PA 3rd joined the main Continental Army and fought at the Battle of Brandywine [11 Sep 1777]. Shortly after Brandywine he was placed in Captain Moffitt’s company and marched to the Battle of Germantown [4 Oct 1777]. After Germantown they wintered at Valley forge. After Valley Forge they fought in the Battle of Monmouth [28 Jun 1778]. After Monmouth, the 3rd PA played a vital role in the Philadelphia, New Jersey and New York areas. In the summer of 1779 they were encamped at Smith’s Clove NY, and the end of 1779 wintered at Morristown. Contrary to his pension statement, the 3rd PA did not move to the Southern Theater but remained in the Northern Theater. He was discharged at Philadelphia in 1783 after serving 6 years.