 In October 1914 Lahm was assigned to the 6th Cavalry at Texas City and Harlingen, Texas until April 1916.Having completed the required years of troop duty in his branch, he was detailed to the Aviation Section, U.S. Signal Corps, which had replaced the Aeronautical Division as the Army's aviation arm in August 1914.Lahm's rating was changed to that of Junior Military Aviator and he was placed on flying duty again.