When the United States entered the war, the United States Army Air Service convened a medical board to recruit Americans serving in the Lafayette Flying Corps for the Air Service of the American Expeditionary Forces. Bullard went through the medical examination, but he was not accepted, as only white pilots were chosen. Some time later, while on a short break from duty in Paris, Bullard allegedly got into an argument with a French commissioned officer and was punished by being transferred to the service battalion of the 170th in January 1918. He served beyond the Armistice, not being discharged until October 24, 1919.