Western Front, France, October 22, 1918. Between 1910 and 1917 a number of aviation units were organized in the National Guard. While only the 1st Aero Company, New York National Guard, was federally recognized, a number of other states had aircraft, and some 100 National Guardsmen took flight training. But when the U.S. entered World War I, the War Department decided not to mobilize National Guard aviation units, and so National Guard aviators entered Federal service as individuals. First Lieutenant Reed M. Chambers, a former Tennessee Guardsman, was assigned to the 94th Aero Squadron along with Eddie Rickenbacker, who would become the leading American ace of the war. The squadron arrived in France on March 4, 1918, and one month later became the second American flying unit to see action, credited with two kills on its first day in combat. The 94th participated in the Chateau-Thierry and Aisne-Marne campaigns, and then in the Meuse-Argonne offensive, the largest U.S. operation of the war. By William S. Phillips, National Guard Series