ARLINGTON, VIRGINIA – NOVEMBER 11: Troops march during a full honors procession commemorating the 100th anniversary of the Tomb of the Unknown Soldier on November 11, 2021 at Arlington National Cemetery in Arlington, Virginia. The Tomb of the Unknown Soldier, serving as the heart of Arlington National Cemetery, has provided a final resting place for one of America’s unidentified World War I service members, and unidentified soldiers from later wars were added in 1958 and 1984. The tomb plaza is open to the public this week for the first time in almost a hundred years. (Photo by Sarah Silbiger-Pool/Getty Images)