 In December 1928, after serving as Officer-in-Charge of Land Transportation at the Marine Barracks, Parris Island, South Carolina, he joined the 1st Brigade Marines in Haiti, and became aide to the commanding general.He returned to the United States in June 1931, entering the Army Infantry School at Fort Benning, Georgia, the following September.Graduating in June 1932, Thomas was made an instructor in the Basic School at the Philadelphia Navy Yard.