Douglas McDougal was appointed a Naval Cadet in in the U.S. Naval Academy at Annapolis, Class of 1897 but resigned in 1894. He re-enlisted in the Navy at in 1898 at the opening of hostilities in the Spanish-American War. He was appointed an Ensign and served in that capacity until he was honorably discharged. He was appointed a Marine Corps second lieutenant in 1900 and subsequently in 1940 as a U.S. Marine Corps Major General.