The roar begins in the parking lot at the Pentagon. Within minutes, the slow rumble, mostly of Harley-Davidson motorcycles, makes its way onto Memorial Bridge. Thus begins the Rolling Thunder's First Amendment Demonstration Run. Founded in 1987, the organization raises awareness for people listed as prisoners of war or missing in action in all wars going back to World War I. After making its way across the Memorial Bridge, the wave of motorcycles passes the Lincoln Memorial, rolls onto Constitution Avenue, and rumbles past the National Mall to the Capitol. The bikers then make their way to Independence Avenue and drive past the Mall again before completing their run at Potomac Park, where the cavalcade pays tribute to America's fallen soldiers. The event continues with speakers at the Lincoln Memorial, followed by a musical tribute...