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The Pentagon

The Pentagon is the headquarters building of the United States Department of Defense, in Arlington County, Virginia, across the Potomac River from Washington, D.C. The building was constructed on an accelerated schedule during World War II. As a symbol of the U.S. military, the phrase The Pentagon is often used as a metonym for the Department of Defense and its leadership.

"The Pentagon" is also a metonym for the United States Department of Defense. For other uses, see The Pentagon (disambiguation).

The Pentagon

Richmond Hwy./VA 110 at I-395, Arlington County, Virginia, U.S.

11 September 1941 (1941-09-11)

15 January 1943 (1943-01-15)

$83 million (equivalent to $1.33 billion in 2023)[1]

77 ft (23 m)[2]

7 (2 underground)

6,636,360 sq ft (620,000 m2)

George Bergstrom
David J. Witmer

John McShain, Inc.

67 acres (27 ha)

000-0072

27 July 1988

18 April 1989[4]

The building was designed by American architect George Bergstrom and built by contractor John McShain. Ground was broken on 11 September 1941, and the building was dedicated on 15 January 1943. General Brehon Somervell provided the major impetus to gain Congressional approval for the project;[5] Colonel Leslie Groves was responsible for overseeing the project for the U.S. Army Corps of Engineers, which supervised it.


The Pentagon is the world's second largest office building, with about 6.5 million square feet (600,000 m2) of floor space, of which 3.7 million square feet (340,000 m2) are used as offices.[6][7] It has five sides, five floors above ground, two basement levels, and five ring corridors per floor with a total of 17.5 mi (28.2 km)[7] of corridors, with a central five-acre (2.0 ha) pentagonal plaza. About 23,000 military and civilian employees work in the Pentagon, as well as about 3,000 non-defense support personnel.[7]


In 2001, the Pentagon was damaged during the September 11 attacks. Five al-Qaeda hijackers flew American Airlines Flight 77 into the western side of the building, killing themselves and 184 other people: 59 on the airplane and 125 in the Pentagon.[8] It was the first significant foreign attack on federal facilities in the capital area since the burning of Washington during the War of 1812. Following the attacks, the western side of the building was repaired, with a small indoor memorial and chapel added at the point of impact. An outdoor memorial dedicated to the Pentagon victims of 9/11 opened in 2008.

View of the Pentagon from the northwest during the building's construction in July 1942

View of the Pentagon from the northwest during the building's construction in July 1942

A view of the Pentagon from the southwest with the Potomac River and Washington Monument in background in 1988

A view of the Pentagon from the southwest with the Potomac River and Washington Monument in background in 1988

Aftermath at the Pentagon from the September 11 attacks

Aftermath at the Pentagon from the September 11 attacks

A September 11 anniversary illumination at the Pentagon in 2007

A September 11 anniversary illumination at the Pentagon in 2007

The Pentagon 9/11 Memorial, a tribute to the lives lost in the Flight 77's collision with the Pentagon in the September 11 attacks, which killed 125 people in the Pentagon and all 64 on board Flight 77

The Pentagon 9/11 Memorial, a tribute to the lives lost in the Flight 77's collision with the Pentagon in the September 11 attacks, which killed 125 people in the Pentagon and all 64 on board Flight 77

An aerial closeup of the Pentagon in May 2021

An aerial closeup of the Pentagon in May 2021

List of National Historic Landmarks in Virginia

List of United States military bases

National Register of Historic Places listings in Arlington County, Virginia

Pentagon Force Protection Agency

headquarters of the Egyptian Ministry of Defense in the New Administrative Capital

The Octagon

(archived version)

The Pentagon website

one of earliest World War II articles on the Pentagon

Popular Mechanics, March 1943, "Army's Giant Five-by-Five"

Pentagon Force Protection Agency

 – The Washington Post, 26 May 2007

How the Pentagon Got Its Shape

U.S. Geological Survey Geographic Names Information System: The Pentagon