U.S. Army Training and Doctrine Command Soldiers salute during the National Anthem at the Army Reserves’ Birthday Celebration Run at Joint Base Langley-Eustis, Va., April 21, 2017. The Army Reserve was established on April 23, 1908 when Congress authorized the Army to form a Medical Reserve Corps. (U.S. Air Force photo/Airman 1st Class Kaylee Dubois)