U.S. Air Force 633rd Security Forces Squadron military working dog, Largo, poses for a photo during a ruck march in honor of National K9 Veterans Day at Joint Base Langley-Eustis, Virginia, March 13, 2020. On March 13, 1942, the U.S. Army started training for its new War Dog Program, which marked the first time dogs were officially members of the U.S. Armed Forces. (U.S. Air Force photo by Staff Sgt. Kaylee Dubois)