“We’re preparing for an enormous turnout,” said Matt McCool of the Secret Service's Washington Field office, who said more than 18 miles of “anti-scale fencing” would be erected and “multiple drones” would be in the air. The entire District of Columbia is normally a no-fly zone for drones.

Hundreds of military vehicles will take to the streets of D.C. on June 14 as part of a military parade and celebration of the 250th birthday of the U.S. Army.