There was a heightened fear of of aerial bombardment early in the war, best embodied by Stanley Baldwin’s famous warning that “the bomber will always get through.” District residents saw the Luftwaffe bombing of Buckingham Palace and Westminster Abbey and were concerned that DC’s symbolic value would make the city a compelling target.

Washington was never at risk in the same way as other wartime capitals such as Paris or London, but the military did put up some anti-aircraft defenses just to be sure.

Auto cannons (commonly dubbed “ack ack” guns) and machine guns were placed around the city and on the rooftops of government buildings along the Mall.