Row upon row of white marble monuments at Arlington National Cemetery honor military veterans. More than 400,000 graves line up on its 624 acres, which also hold the Tomb of the Unknowns and the grave of John F. Kennedy. (The Washington Times)

Row upon row of white marble monuments at Arlington National Cemetery honor military veterans. More than 400,000 graves line up on its 624 acres, which also hold the Tomb of the Unknowns and the grave of John F. Kennedy. (The Washington Times)