Jim Harper, who served in the Navy from 1969-1973, rode in Rolling Thunder 2013. At the Pentagon in Arlington, Va., thousands of motorcyclists gathered to participate in the 26th "Rolling Thunder" motorcycle rally, May 26, 2013. The event is in its 26th year now. Participants from around the United States gathered at the Pentagon before embarking on a ride around the National Mall in Washington, D.C. The rally brings attention to prisoners of war and those missing in action.