Garnett served in the US Army, off and on, over some 4 decades. It doesn’t seem to have been so much of a vocation, as perhaps a more serious adventuring. The story I heard, unlikely to be exactly true, is that he and his best friend Albert Collins loaded themselves up with their horses and supplies and headed out to by train to join the Spanish-American war on the Mexican border. The official version is more like Enlisted, July 5, 1915, in Troop B, Squadron A Cavalry, NYNG, New York City. He mustered in , June 30, 1916, for service on the Mexican border, with Troop B, Squadron A Cavalry. Squadron A was assigned to Camp McAllen, Texas with the 6th New York Division. In any event Garnett served in the military supply corps in WWI with the AEF. In WWII he was Director of Overseas Supply (Lt. Col.) operating out of Norfolk, VA. He received various medals and honors from the US, French and even Russians during his Army service.