Harold Julius Chapman was born in Kansas, on February 16, 1898, son of Mrs. Clara (Greene) Chapman and the late Dr. Harold J. Chapman. He attended Logan (Kansas) High School, and was appointed to the US Military Academy, West Point, New York. Graduated on June 15, 1920, he was commissioned Second Lieutenant in the US Army. He resigned his commission on March 11, 1921, and for a year thereafter attended Massachusetts Institute of Technology at Cambridge. In 1925 he graduated from the University of Chicago, Illinois, with the degree of Bachelor of Science, and in 1929 received the degree of Doctor of Medicine from Rush Medical College, also in Chicago.
Prior to entering the Naval service, he was engaged in private general surgical practice in Los Angeles, California. On February 7, 1941, he was appointed a Lieutenant Commander in the Medical Corps of the US Naval Reserve, and subsequently advanced in rank to that of Captain, to date from March 10, 1945. On June 15, 1946 he transferred from the Reserve to the Regular Navy.
Upon receiving his appointment in 1941, he was assigned to the Destroyer Base, San Diego, California. He remained there until March 1942, when he joined USS Raleigh as Senior Medical Officer, serving as such during the Aleutian Campaign and until March 1943. Detached from the Raleigh, he was ordered to the Mayo Clinic, Rochester, Minnesota, for a postgraduate course in general surgery. Completing his instruction in February 1944, he then had duty at the Naval Hospital, Long Beach, California. In June 1944 he reported as Head of the Surgical Division at the US Naval Training Center, San Diego, California.
Between March and September 1945, he served with Fleet Hospital #103, Guam, Marianas Islands, after which he had duty as Chief of Surgery at Fleet Hospital #107, Okinawa, Ryukyu Islands. In September 1945 he joined USS Consolation as Chief of Surgery. Detached from that hospital ship in February 1946, he was in command of the Naval Dispensary, Long Beach, California, until September 1946. He became Chief of Surgery at the Naval Hospital, Seattle, Washington, continuing duty in that assignment until March 1947, when he transferred to the Naval Hospital, Philadelphia, Pennsylvania, as Assistant Chief of Surgery. He remained there until November 1947, when he reported in a similar capacity to the Naval Hospital, Oakland, California, also serving as Acting Chief of Surgery there. In June 1951 he assumed command he became the Chief of Surgery if the US Naval Hospital, Corona, and organized that Department, and to date (January 1952), is the Chief of Surgical Service.
Captain Chapman has the World War I Victory Medal; the American Defense Service Medal; the American Campaign Medal; the Asiatic-Pacific Campaign Medal with two engagement stars; and the World War II Victory Medal.