Col. Kevin Kennedy, 28th Bomb Wing commander, leads 15 military recruits in reciting the oath of enlistment as part of a military appreciation ceremony at the Mount Rushmore National Memorial in South Dakota, July 3, 2013. The oath of enlistment dates back to the Revolutionary War, when the Continental Congress established oaths for enlisted men and officers. (U.S. Air Force photo by Airman 1st Class Zachary Hada/Released)