Harry Markoe was born in Philadelphia on December 15, 1846, the son of James Markoe and Sarah C. Fisher.
Markoe entered the University in 1861 as a freshman member of the College Class of 1865. Like his brother James Markoe, Jr., Class of 1863, he joined Delta Phi fraternity. He was also a member of the sophomore Boat Club and the sophomore cricket team, and a corporal in the University Light Infantry. Harry Markoe left the University during his senior year before receiving a degree. As an alumnus, Markoe continued to row in the University Barge Club for several years, serving as the club’s secretary in 1867.
After his college years, Harry Markoe became a stockbroker. He married Frances Eustis Caldwell. Markoe died at his home in Penllyn, Pennsylvania, on July 15, 1929.