He was a Marine.
Thanks for the correction. That tailgunner moniker made me assume Army Air Corps bombers. Douglas Dauntless dive bombers had machine guns facing the rear, but the guns and gunner were in the cockpit.
He served in the U.S. Navy from 1956 to 1960; one of his assignments was as an intelligence briefer for Admiral Arleigh Burke. He achieved the rank of Lieutenant, Junior Grade.