LANGLEY AIR FORCE BASE, Va. -- Airman 1st Class Amy Aguilera, U.S. Air Force Heritage of America Band vocalist, performs the national anthem during the 2009 Yorktown Day in Yorktown, Va., Oct. 19. Yorktown Day commemorates the Battle of Yorktown, which brought an end to the American Revolutionary War. (U.S. Air Force photo/Senior Airman Zachary Wolf)