The U.S. Army is celebrating its 250th birthday in Washington, D.C. with a massive festival, parade and concert. The parade will go down Constitution Avenue, from 23rd Street to 15th Street in Washington,

The parade kicks off from the Lincoln Memorial, include about 6,600 soldiers, 50 helicopters and 60-ton M1 Abrams battle tanks, as well as possibly 200,000 attendees and heightened security to match,