Charles Long graduated from the U.S. Naval Academy at Annapolis, Class of 1889, and served in the U.S. Navy for two years before transferring to the Marine Corps. He participated in action during the Spanish-American War earning the Marine Corps Brevet Medal, the Boxer Rebellion in China, and in the Caribbean. Prior to World War I he served as Assistant to the Commandant of the Marine Corps. During World War I he was awarded the Navy Cross for those duties. He retired in 1942 and was promoted to Major General on the retired list.