The Pentagon soon became identified not only with the Army, but with the entire U.S. military. The first secretary of defense, James Forrestal, moved into the Pentagon in September 1947. The Navy, which had tried and failed to negotiate a move to the Pentagon in 1941, moved in a year later. The Marine Corps, clinging stubbornly to its reputation for independence, did not move its headquarters to the Pentagon until 1995.

The National Security Act acknowledged the importance of shared planning and communication among the service branches, and the Pentagon’s internal configuration conformed, over the next half-century, to become the nation’s Cold War command post. The Joint Chiefs Area, including the conference room informally known as “The Tank,” was built near the secretary’s office. Over time, the “war rooms” evolved into the National Military Command System (NMCS), created by Secretary of Defense Robert McNamara in 1962 and consisting of the National Military Command Center (NMCC) in the Pentagon and the National Emergency Airborne Command Post. While command and control organization within the Department of Defense has evolved and adapted over time, the Pentagon’s NMCC has remained its centerpiece. In the mid-1980s, a 5,200-square-foot Crisis Coordination Center was built near the Office of the Secretary of Defense and adjacent to the NMCC, equipped with a computer network and communications equipment for rapid and informed decision-making within the National Command Authority.

The Pentagon’s population declined after World War II, but not in proportion to the postwar demobilization. At full occupancy in 1944, it had a working population of up to 33,000. Unlike the military’s active-duty strength – which peaked at more than 12 million in 1945, spiked at around 3.5 million during the wars in Korea and Vietnam, and has hovered below 1.5 million since 1990 – the number of workers in the Pentagon, aside from surges during the Korean and Vietnam conflicts, has tended to remain near its originally intended occupancy, between 23,000 and 26,000. Despite early predictions, the Pentagon has never accommodated the entire staff of the U.S. military.

The building has, nevertheless, from its very inception, become an avatar, embodying the nation’s transformation into a global power. In 1992, the National Park Service declared the building a National Historic Landmark. This was, strictly speaking, a breach of the minimum eligibility requirements, which required a landmark to be at least 50 years old. “The Pentagon, however,” wrote the nominating committee, “is of an exceptional level of historical significance . . . Its configuration, role, and location have combined to make the Pentagon an essential and important physical and symbolic element of the Monumental Core of the Nation’s Capital.”

 

A Cultural Touchstone

Long before it had been completed, the Pentagon had become an object of intense popular fascination; the construction itself spawned urban legends and apocryphal tales repeated as fact to this day. The enormity and speed of the concrete pours required to build its walls gave rise to stories of men who’d fallen in and been discovered only after the forms were removed to reveal their corpses. There were many of these stories, each so peculiarly detailed that they seemed impossible to have been made up – in fact, as Vogel recounts in his book, one was recycled and printed as gospel in the Pentagon’s official newsletter in 1984.