TRIBUTE TO AMERICA Veterans raise an American flag as they participate in Rolling Thunder on the National Mall in Washington, D.C., May 29, 2011. Rolling Thunder is an annual event in which thousands of veterans ride motorcycles through the city to call attention to prisoners of war and those missing in action. SHARE: Download: Full Size (0.07 MB) Credit: VIRIN: 350371-F-ENV65-341.jpg Photo Gallery