Bryant graduated with Bachelor of Science degree on June 6, 1914, and was commissioned Ensign on that date. He was subsequently assigned to the battleship USS "Wyoming" and took part in the Veracruz Expedition in autumn 1914. Bryant then participated in the patrol cruises in the Caribbean and following the United States' entry into World War I, he sailed for Europe, where he took part in the naval operations with the British Grand Fleet. He was promoted to Lieutenant (junior grade) on June 6, 1917, and to temporary rank of Lieutenant on August 31 that year.