The Pentagon’s most significant architectural legacy isn’t aesthetic, however. It’s so large that it’s more than a building; it’s a micro-society, incorporating offices, maintenance facilities, an indoor shopping mall, and facilities for handling food service, mail, communications, fitness, recreation, medical care, and other services. Upon the building’s completion in 1943, the magazine Architectural Forum observed that the integration of these facilities under a single roof offered “a real foretaste of the future . . . as building approaches the scale technically feasible, the distinction between architecture and city planning vanishes.”

Because of this, the Pentagon has often resembled a microcosm of the greater American society it serves, roiled by the issues of the day. In May 1942, as the first employees were moving in, Roosevelt toured the building and observed that there appeared to be twice as many bathrooms as necessary. At the time, the Commonwealth of Virginia’s Jim Crow laws mandated that new buildings be constructed with separate bathrooms for black and white people, and the officer overseeing the construction, then-Col. Leslie Groves, had complied.

Roosevelt had, nearly a year earlier, issued an executive order ending racial segregation in federal agencies and contractors involved in the war effort, and the restroom segregation was never enforced. The often-written claim that the Pentagon was never segregated, however, isn’t quite true: Vogel recounts an ugly incident, just a couple of weeks after Roosevelt’s visit, in which black workers from the Ordnance Department were turned away from the cafeteria line and directed to a “colored” dining room. The workers’ principled refusal to do so, nearly two decades before the Greensboro sit-ins, resulted in a security guard clubbing one on the skull and drawing his gun. Somervell, furious, ordered Groves to discontinue any enforced segregation in the Pentagon’s dining facilities. Until 1965, in contradiction of Virginia law, the Pentagon was the only non-segregated public building in the state.

As the symbol of America’s military, the Pentagon has, not surprisingly, been a target of anti-war protests. The first was staged in 1965 by a single Baltimore Quaker, Norman Morrison, who committed suicide on the lawn below Secretary of Defense Robert McNamara’s window to protest U.S. involvement in Vietnam.

The largest-ever Pentagon protest was staged two years later, in October 1967, when tens of thousands of demonstrators, a loose association of groups marching under the umbrella of the National Mobilization Committee to End the War in Vietnam (“the Mobe”), descended on the building for a 48-hour anti-war rally. Because some of the protestors had publicly announced their intention to gain entrance to the building and disrupt the work going on there, more than 1,200 military police and guard units were brought in, along with 200 federal marshals, to cordon off the area where the protestors were assembled.

The next 48 hours were by turns violent – in their struggle to breach the lines of defense, protestors threw rocks and bottles, smashed windows, and scuffled with guards, resulting in about 45 injuries – and absurd. Abbie Hoffman, co-founder of the Youth International Party (Yippies), threatened guards with a water pistol filled with LSD. At one point, Hoffman and beatnik poet Allen Ginsburg led a crowd of about 100 in a chant aimed at “levitating” the Pentagon. One of the protestors, the novelist Norman Mailer, chronicled the rally in his Pulitzer Prize-winning book The Armies of the Night, in which he described the Pentagon as “the true and high church of the military-industrial complex . . . Every aspect of the building was anonymous, monotonous, massive, interchangeable.”

The 1967 protests worsened the climate between the government and anti-war protestors, to the point where the Pentagon was attacked. On May 19, 1972, a day chosen to honor the birthday of the late Ho Chi Minh, the anti-war group the Weathermen placed a bomb in a women’s restroom at the Pentagon. Nobody was hurt, but the bomb caused $75,000 in damage.