At field headquarters near Casas Grandes, Mexico, April 1916, airmen Lts. <a href="https://en.wikipedia.org/wiki/Herbert_Dargue" class="extiw" title="w:Herbert Dargue">Herbert A. Dargue</a> (left), and Edgar S. Gorrell (right) pose with Signal Corps No. 43.
United States Army Signal Corps
1916
<a rel="nofollow" class="external free" href="http://www.afhso.af.mil/shared/media/document/AFD-100928-064.pdf">http://www.afhso.af.mil/shared/media/document/AFD-100928-064.pdf</a> The 1st Aero Squadron and the Mexican Punitive Expedition of 1916