Martin was called into active military duty in 1942, serving as a major in the United States Army. He served as the director of the Ground School for the Tuskegee airmen in March of 1943, where he would serve until his death in 1945. Thanks in part to Martin's training, the Tuskegee Airmen became the elite unit they are known as today.
At Norwich University, Martin was the first black student to attend the University. He was a star football player, a hockey captain, a member of the baseball team, and a member of the student council. Martin gained respect among his peers, being elected as a captain to multiple teams.
While at Norwich, he is believed to have been the first black collegiate hockey player in the United States, just one of various firsts that he would accomplish through his life. He was the first black member of the Norwich University Athletic Hall of Fame, and just one of two members from his graduating class to be included.[7]
A widely loved student, at Norwich many took inspiration from Martin and respected him as a member of various clubs and student organizations on campus. His time at Norwich left a mark on the University as they established the Harold "Doc" Martin '20 Memorial Scholarship to assist minority students with paying for college while at Norwich. Beyond that, Norwich established the Harold "Doc" Martin Society to promote acceptance, inclusivity, and diversity on campus.