Master Sgt. Ryan Carson, U.S. Air Force Band, Vocalist for Max Impact alongside U.S. Marines sing the ?Marine Hymn? during the National Parks Service Independence Day Celebration at the Washington Monument July 4. Tens of thousands of guests attend the event at National Mall including distinguished visitors, ?Wounded Warriors? from Walter Reed Army Medical Center. (U.S. Air Force photo / Staff Sgt. Nichelle Anderson)