The cannon of the Presidential Salute Gun Platoon roar in succession, a rolling volley honoring a new president. The ceremonial unit is part of the U.S. Army's Headquarters and Headquarters Company, 1st Battalion, 3rd Infantry Regiment, "The Old Guard," based on Fort Myer, Va. More than 5,000 men and women in uniform are providing military ceremonial support to the presidential inauguration, a tradition dating back to George Washington's 1789 inauguration. DoD photo by U.S. Air Force Senior Airman Kathrine McDowell