Manson spent much of his life in Columbia, S.C., and his family returned there shortly before his death. He had enlisted in the Marine Corps in May 1967. The 20-year-old lance corporal died in the Station Hospital in Da Nang, Quang Nam Province, Vietnam on July 25, 1968, the day he was struck by a bullet from a rifle being cleaned by a fellow Marine in Company K of the 3rd Battalion, 1st Marines, and 1st Marine Division. He was survived by his father, four brothers and three sisters.