America in Photos: Tomb of the Unknown Soldier, ‘Killed to Order’ Book Launch, and 100K Ultramarathon

The ceremonial changing of the guards at the Tomb of the Unknown Soldier takes place as the sun rises over Arlington National Cemetery in Arlington, Va., on March 17, 2026. March 25 will mark the centennial of the continuous military sentinel guarding the Tomb of the Unknown Soldier. (Heather Diehl/Getty Images)