He was a member of the first Waycross High School tennis team. He won school and district honors in singles and doubles in 1933, 1934 and 1935, and the district championship in singles in 1935. He was a member of the district and state doubles champions in 1935.
At South Georgia College in 1936, Harper won the state singles championship and repeated in 1937.
At Presbyterian College, he was a member of the state intercollegiate doubles team in 1938. He won the state singles event and was a part of the doubles intercollegiate championship team in 1939.
Harper would say “whatever success he had in life was directly related to a tennis racquet because it enabled him to obtain a college education.”