THE U.S. Capitol Building stands regally at the eastern end of the National Mall, on a raised plateau that city designer Pierre L’Enfant described as “a pedestal waiting for a monument.” The Capitol’s massive footprint measures more than 750 feet in length and 350 feet deep. Housing more than sixteen acres of floor space, it contains an astonishing 541 rooms. The neoclassical architecture is meticulously designed to echo the grandeur of ancient Rome, whose ideals were the inspiration for America’s founders in establishing the laws and culture of the new republic.

The new security checkpoint for tourists entering the Capitol Building is located deep within the recently completed subterranean visitor center, beneath a magnificent glass skylight that frames the Capitol Dome. Newly hired security guard Alfonso Nuñez carefully studied the male visitor now approaching his checkpoint. The man had a shaved head and had been lingering in the lobby, completing a phone call before entering the building. His right arm was in a sling, and he moved with a slight limp. He was wearing a tattered army-navy surplus coat, which, combined with his shaved head, made Nuñez guess military. Those who had served in the U.S. armed forces were among the most common visitors to Washington.

“Good evening, sir,” Nuñez said, following the security protocol of verbally engaging any male visitor who entered alone.