The Pentagon

The Pentagon
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Name	The Pentagon
Caption	Aerial view showing the distinctive five-sided design.
Location	Arlington, Virginia, U.S.
Coordinates	38, 52, 15, N...
Start date	September 11, 1941
Completion date	January 15, 1943
Architect	George Bergstrom
Owner	United States Department of Defense
Building type	Office building
Architectural style	Stripped Classicism
Floor count	7 (5 above ground, 2 below)
Floor area	6,636,360 sq ft (616,500 m²)

The Pentagon. It is the headquarters of the United States Department of Defense and one of the world's largest office buildings. Located in Arlington, Virginia, just across the Potomac River from Washington, D.C., it serves as a symbol of the U.S. military. Its unique five-sided design and immense scale are recognized globally, housing the command centers for the Army, Navy, Air Force, Space Force, Marine Corps, and the office of the Secretary of Defense.

History and construction

The urgent need for a consolidated War Department headquarters during World War II drove its creation. President Franklin D. Roosevelt approved the project, and architect George Bergstrom finalized the unique pentagonal design to fit the irregularly shaped tract of land. Construction began on September 11, 1941, under the direction of Leslie Groves, who later oversaw the Manhattan Project. Built primarily of reinforced concrete, the structure was completed in a remarkable 16 months, with employees moving in by 1942, even as work continued. The site, once known as Arlington Farm, was part of the Arlington National Cemetery vicinity and previously owned by Confederate General Robert E. Lee.

Architecture and layout

The building is a classic example of Stripped Classicism, emphasizing functionality over ornamentation. Its five concentric rings, labeled A through E from the center outward, are connected by ten spoke-like corridors, minimizing walking distance between any two points. The central five-acre plaza, informally called "Ground Zero," is the hub of this radial design. Despite its vast 6.6 million square feet of floor space, a person can walk between any two locations within approximately seven minutes. The complex includes a Metro station, The Pentagon Memorial, and numerous internal amenities like food courts and retail stores to serve its daily population.

Functions and operations

It houses the senior leadership and command elements for all branches of the U.S. military. Key offices include those of the Secretary of Defense, the Joint Chiefs of Staff, and the service secretaries for the Army, Navy, and Air Force. Major operational commands, such as the United States Cyber Command and elements of the United States Northern Command, are also based within its rings. The National Military Command Center, a secure communications hub, operates continuously to monitor global events and direct forces. Approximately 23,000 military and civilian employees work there, coordinating policy, intelligence, logistics, and budget for the United States Armed Forces.

Role in national defense

As the nerve center of the United States Department of Defense, it is integral to the command and control of U.S. military operations worldwide. Critical decisions during conflicts from the Vietnam War and the Gulf War to the War in Afghanistan and the Iraq War were made within its walls. It plays a central role in the planning and execution of national security strategy, working in concert with the White House, the Congress, and agencies like the CIA and the NSA. The building also hosts high-level meetings with foreign defense officials, such as those from NATO and key allies, reinforcing international military partnerships.

Notable events and incidents

The most devastating event in its history was the September 11, 2001 terrorist attacks, when American Airlines Flight 77 was hijacked and crashed into the western side, killing 184 people. This led to a major reconstruction project known as the Phoenix Project. During the Cold War, it was a key target in nuclear war plans, such as the Single Integrated Operational Plan. It has also been the site of significant protests, including the 1967 March on the Pentagon against the Vietnam War, and was breached during the January 6, 2021 unrest. In 1972, a bomb planted by the Weather Underground exploded in a restroom, causing damage but no injuries.

Category:Buildings and structures in Arlington County, Virginia Category:United States Department of Defense Category:Headquarters of government departments and agencies