The Pentagon is the
headquarters
Headquarters (commonly referred to as HQ) denotes the location where most, if not all, of the important functions of an organization are coordinated. In the United States, the corporate headquarters represents the entity at the center or the to ...
building of the
United States Department of Defense. It was constructed on an accelerated schedule during
World War II. As a symbol of the
U.S. military
The United States Armed Forces are the military forces of the United States. The armed forces consists of six service branches: the Army, Marine Corps, Navy, Air Force, Space Force, and Coast Guard. The president of the United States is the ...
, the phrase ''The Pentagon'' is often used as a
metonym
Metonymy () is a figure of speech in which a concept is referred to by the name of something closely associated with that thing or concept.
Etymology
The words ''metonymy'' and ''metonym'' come from grc, μετωνυμία, 'a change of name' ...
for the Department of Defense and its leadership.
Located in
Arlington County, Virginia, across the
Potomac River from
Washington, D.C., the building was designed by American architect
George Bergstrom
George Edwin Bergstrom (March 12, 1876 – June 17, 1955) was an American architect who designed The Pentagon in Arlington County, Virginia.
Biography
George Edwin Bergstrom was born in Neenah, Wisconsin, of Norwegian immigrant ancestry. His ...
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
Brehon Burke Somervell (9 May 1892 – 13 February 1955) was a general in the United States Army and Commanding General of the Army Service Forces in World War II. As such he was responsible for the U.S. Army's logistics. Following his death, ' ...
provided the major impetus to gain Congressional approval for the project; 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
largest office building, with about of
floor space
In architecture, construction, and real estate, floor area, floor space, or floorspace is the area (measured as square feet or square metres) taken up by a building or part of it. The ways of defining "floor area" depend on what factors of the buil ...
, of which are used as offices.
Some 23,000
military and
civilian employees,
and another 3,000 non-defense support personnel, work in the Pentagon. It has five sides, five floors above ground, two basement levels, and five ring corridors per floor with a total of
of corridors. The central pentagonal plaza is nicknamed "
ground zero" on the presumption that it would be a prime target in a
nuclear war
Nuclear warfare, also known as atomic warfare, is a theoretical military conflict or prepared political strategy that deploys nuclear weaponry. Nuclear weapons are weapons of mass destruction; in contrast to conventional warfare, nuclear w ...
.
In 2001, the Pentagon was damaged during the
September 11 attacks. Five
al-Qaeda
Al-Qaeda (; , ) is an Islamic extremism, Islamic extremist organization composed of Salafist jihadists. Its members are mostly composed of Arab, Arabs, but also include other peoples. Al-Qaeda has mounted attacks on civilian and military ta ...
hijackers flew
American Airlines Flight 77
American Airlines Flight 77 was a scheduled American Airlines domestic transcontinental passenger flight from Washington Dulles International Airport in Dulles, Virginia, to Los Angeles International Airport in Los Angeles, California. The Boe ...
into the western side of the building, killing themselves and 184 others: 59 on the airplane and 125 in the Pentagon. It was the first significant foreign attack on Washington's governmental facilities since
the city was burned by the British 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.
Layout and facilities
The Pentagon building spans , and includes an additional as a central courtyard.
Starting with the north side and moving
clockwise, its five façade entrances are the Mall Terrace, the River Terrace, the Concourse (or Metro Station), the South Parking, and the Heliport. On the north side of the building, the Mall Entrance, which also features a portico, leads out to a terrace that is used for ceremonies. The River Entrance, which features a
portico
A portico is a porch leading to the entrance of a building, or extended as a colonnade, with a roof structure over a walkway, supported by columns or enclosed by walls. This idea was widely used in ancient Greece and has influenced many cult ...
projecting out , is on the northeast side, overlooking the lagoon and facing Washington. A stepped terrace on the River Entrance leads down to the lagoon; and a landing dock was used until the late 1960s to ferry personnel between
Bolling Air Force Base and the Pentagon. The main entrance for visitors is on the southeast side, as are the
Pentagon Metro station and the bus station.
There is also a concourse on the southeast side of the second floor of the building, which contains a mini-shopping mall. The south parking lot adjoins the southwest façade, and the west side of the Pentagon faces
Washington Boulevard.
The concentric rings are designated from the center out as "A" through "E" (with additional "F" and "G" rings in the basement). "E" Ring offices are the only ones with outside views and are generally occupied by senior officials. Office numbers go clockwise around each of the rings, and have two parts: a nearest-corridor number (1 to 10), followed by a bay number (00 to 99), so office numbers range from 100 to 1099. These corridors radiate out from the central courtyard, with corridor 1 beginning with the Concourse's south end. Each numbered radial corridor intersects with the corresponding numbered group of offices (for example, corridor 5 divides the 500 series office block). There are a number of historical displays in the building, particularly in the "A" and "E" rings.
Subterranean floors in the Pentagon are lettered "B" for Basement and "M" for
Mezzanine
A mezzanine (; or in Italian language, Italian, a ''mezzanino'') is an intermediate floor in a building which is partly open to the double-height ceilinged floor below, or which does not extend over the whole floorspace of the building, a loft ...
. The concourse is on the second floor at the Metro entrance. Above-ground floors are numbered 1 to 5. Room numbers are given as the floor, concentric ring, and office number (which is in turn the nearest corridor number followed by the bay number). Thus, office 2B315 is on the second floor, B ring, and nearest to corridor 3 (between corridors 2 and 3). One way to get to this office would be to go to the second floor, get to the A (innermost) ring, go to and take corridor 3, and then turn left on ring B to get to bay 15.
It is possible for a person to walk between any two points in the Pentagon in less than ten minutes, though the most optimal route may involve a brisk walk, routing through the open-air central courtyard, or both.
The complex includes eating and exercise facilities, and meditation and prayer rooms.
Just south of the Pentagon are
Pentagon City and
Crystal City, extensive shopping, business, and high-density residential districts in
Arlington.
Arlington National Cemetery is to the north. The Pentagon is surrounded by the relatively complex
Pentagon road network.
The Pentagon has six Washington, DC,
ZIP Codes (despite its location in Virginia): The Secretary of Defense, the Joint Chiefs of Staff, and the four service branches each have their own ZIP Code.
History
Background
Before the Pentagon was built, the
United States Department of War was headquartered in the
Munitions Building, a temporary structure erected during
World War I along
Constitution Avenue on the
National Mall
The National Mall is a Landscape architecture, landscaped park near the Downtown, Washington, D.C., downtown area of Washington, D.C., the capital city of the United States. It contains and borders a number of museums of the Smithsonian Institut ...
. The War Department, which was a civilian agency created to administer the
U.S. Army, was spread out in additional temporary buildings on the National Mall, as well as dozens of other buildings in Washington, D.C.,
Maryland and
Virginia. In the late 1930s, during the Great Depression and federal construction program, a
new War Department Building was constructed at 21st and C Streets in
Foggy Bottom but, upon completion, the new building did not solve the department's space problem. It became the headquarters of the
Department of State
The United States Department of State (DOS), or State Department, is an executive department of the U.S. federal government responsible for the country's foreign policy and relations. Equivalent to the ministry of foreign affairs of other nati ...
.
When
World War II broke out in Europe in 1939, the War Department rapidly expanded to deal with current issues and in anticipation that the United States would be drawn into the conflict. Secretary of War
Henry L. Stimson found the situation unacceptable, with the Munitions Building overcrowded and department offices spread out in additional sites.
Stimson told U.S. President
Franklin D. Roosevelt in May 1941 that the War Department needed additional space. On 17 July 1941, a congressional hearing took place, organized by Congressman
Clifton Woodrum
Clifton Alexander Woodrum (April 27, 1887 – October 6, 1950) was a Virginia pharmacist, lawyer and U.S. Representative from Roanoke who was considered a Progressive Democrat for his support of President Franklin D. Roosevelt.
Early and family ...
(D-VA), regarding proposals for new War Department buildings. Woodrum pressed Brigadier General
Eugene Reybold
Eugene Reybold (February 13, 1884 – November 21, 1961) was distinguished as the World War II Chief of Engineers who directed the largest United States Army Corps of Engineers in the nation's history.
Reybold was born in Delaware City, Delaware ...
, who was representing the War Department at the hearing, for an "overall solution" to the department's "space problem", rather than building yet more temporary buildings. Reybold agreed to report back to the congressman within five days. The War Department called upon its construction chief, General
Brehon Somervell
Brehon Burke Somervell (9 May 1892 – 13 February 1955) was a general in the United States Army and Commanding General of the Army Service Forces in World War II. As such he was responsible for the U.S. Army's logistics. Following his death, ' ...
, to come up with a plan.
Planning
Government officials agreed that the War Department building, officially designated Federal Office Building No 1, should be constructed across the
Potomac River, in
Arlington County, Virginia. Requirements for the new building were that it be no more than four stories tall, and that it use a minimal amount of steel to reserve that resource for war needs. The requirements meant that, instead of rising vertically, the building would be sprawling over a large area. Possible sites for the building included the
Department of Agriculture
An agriculture ministry (also called an) agriculture department, agriculture board, agriculture council, or agriculture agency, or ministry of rural development) is a ministry charged with agriculture. The ministry is often headed by a minister f ...
's
Arlington Experimental Farm, adjacent to
Arlington National Cemetery, and the obsolete
Hoover Field site.
The site originally chosen was
Arlington Farms, which had an asymmetric, roughly pentagonal shape, so the building was planned accordingly as an irregular pentagon. Concerned that the new building could obstruct the view of Washington, D.C., from Arlington Cemetery, President Roosevelt ended up selecting the Hoover Airport site instead. The building retained the pentagonal layout because Roosevelt liked it and a major redesign at that stage would have been costly. Freed of the constraints of the Arlington Farms site, the building was modified as a
regular pentagon
In geometry, a pentagon (from the Greek πέντε ''pente'' meaning ''five'' and γωνία ''gonia'' meaning ''angle'') is any five-sided polygon or 5-gon. The sum of the internal angles in a simple pentagon is 540°.
A pentagon may be simpl ...
. It resembled star
forts constructed during the gunpowder age.
On 28 July,
Congress authorized funding for a new Department of War building in
Arlington, which would house the entire department under one roof.
President Roosevelt officially approved of the Hoover Airport site on 2 September. While the project went through the approval process in late July 1941, Somervell selected the contractors, including John McShain, Inc. of
Philadelphia, which had built
Washington National Airport
Ronald Reagan Washington National Airport , sometimes referred to colloquially as National Airport, Washington National, Reagan National Airport, DCA, Reagan, or simply National, is an international airport in Arlington County, Virginia, across ...
in Arlington, the
Jefferson Memorial in Washington, and the
National Naval Medical Center in
Bethesda, Maryland, along with Wise Contracting Company, Inc. and Doyle and Russell, both from Virginia. In addition to the Hoover Airport site and other government-owned land, construction of the Pentagon required an additional , which were acquired at a cost of $2.2 million (equivalent to $ in ). The Hell's Bottom neighborhood, consisting of numerous pawnshops, factories, approximately 150 homes, and other buildings around
Columbia Pike, was cleared to make way for the Pentagon. Later, of land were transferred to
Arlington National Cemetery and to
Fort Myer, leaving for the Pentagon.
Construction
Contracts totaling $31,100,000 (equivalent to $ in ) were finalized with McShain and the other contractors on 11 September 1941, and ground was broken for the Pentagon the same day. Among the design requirements, Somervell required the structural design to accommodate floor loads of up to , which was done in case the building became a records storage facility at some time after the end of the current war. A minimal amount of steel was used as it was in short supply during World War II. Instead, the Pentagon was built as a reinforced concrete structure, using 680,000 tons of sand dredged from the
Potomac River, and a lagoon was created beneath the Pentagon's river entrance. To minimize steel usage, concrete ramps were built rather than installing elevators.
Indiana limestone was used for the building's façade.
Architectural and structural design work for the Pentagon proceeded simultaneously with construction, with initial drawings provided in early October 1941, and most of the design work completed by 1 June 1942. At times the construction work got ahead of the design, with different materials used than those specified in the plans. Pressure to speed up design and construction intensified after the
attack on Pearl Harbor on 7 December 1941, with Somervell demanding that of space at the Pentagon be available for occupation by 1 April 1943. David J. Witmer replaced Bergstrom as chief architect on 11 April after Bergstrom resigned. Unrelated to the Pentagon project, he was charged with improper conduct while having served as president of the
American Institute of Architects. Construction was completed 15 January 1943.
Soil conditions of the siteon the
Potomac River floodplainpresented challenges, as did the varying
elevations across the site, which ranged from above
sea level. Two retaining walls were built to compensate for the elevation variations, and cast-in-place piles were used to deal with the soil conditions. Construction of the Pentagon was completed in approximately 16 months at a total cost of $83 million (equivalent to $ in ). The building's approximate height is , and each of the five sides is in length.
The building was built wedge by wedge; each wedge was occupied as soon as it was completed, even as construction continued on the remaining wedges.
The Pentagon was designed in accordance with the
racial segregation laws in force in the state of Virginia at the time, with separate eating and lavatory accommodations for white and black persons. While the sets of lavatories were side by side, the dining areas for blacks were located in the basement.
When Roosevelt visited the facility before its dedication, he ordered removal of the "Whites Only" signs in segregated areas. When the Governor of Virginia protested, Roosevelt's administration responded that the Pentagon, although on Virginia land, was under Federal jurisdiction. In addition, its military and civilian Federal employees were going to comply with the President's policies. As a result, the Pentagon was the only building in Virginia where racial segregation laws were not enforced (these laws were not overturned until 1965). The side-by-side sets of restrooms still exist, but have been integrated in practice since the building was occupied.
Hall of Heroes
On the building's main concourse is the Hall of Heroes, opened 1968 and dedicated to the more than 3,460 recipients of the
Medal of Honor, the United States' highest military decoration.
The three versions of the Medal of HonorArmy, Sea Service (for the
Marine Corps,
Navy, and
Coast Guard), and Air Force (for the
Air Force and
Space Force)are on display along with the names of recipients.
The Hall is also used for promotions, retirements, and other ceremonies.
Renovation
From 1998 to 2011, the Pentagon was completely gutted and reconstructed in phases to bring it up to modern standards and improve security and efficiency.
Asbestos
Asbestos () is a naturally occurring fibrous silicate mineral. There are six types, all of which are composed of long and thin fibrous crystals, each fibre being composed of many microscopic "fibrils" that can be released into the atmosphere b ...
was removed and all office windows were sealed.
As originally built, most Pentagon office space consisted of open bays which spanned an entire ring. These offices used
cross-ventilation from operable windows instead of air conditioning for cooling. Gradually, bays were subdivided into private offices with many using
window air conditioning units. With renovations now complete, the new space includes a return to open office bays, and a new Universal Space Plan of standardized office furniture and partitions developed by Studios Architecture.
Pentagon tours were suspended during the
COVID-19 pandemic.
Incidents
Protests
During the late 1960s, the Pentagon became a focal point for protests against the
Vietnam War. A group of 2,500 women, organized by
Women Strike for Peace, demonstrated outside Secretary of Defense
Robert S. McNamara's office at the Pentagon on 15 February 1967. In May 1967, a group of 20 demonstrators held a sit-in outside the Joint Chiefs of Staff's office, which lasted four days before they were arrested. In one of the better known incidents, on 21 October 1967, some 35,000 anti-war protesters organized by the
National Mobilization Committee to End the War in Vietnam, gathered for a demonstration at the Defense Department (the "March on the Pentagon"). They were confronted by some 2,500 armed soldiers. During the protest, a
famous picture was taken, where
George Harris placed
carnations into the soldiers' gun barrels. The march concluded with an attempt to "exorcise" the building.
On 19 May 1972, the
Weather Underground Organization bombed a fourth-floor women's restroom, in "retaliation" for the
Nixon administration's
bombing of Hanoi in the final stages of the
Vietnam War.
On 17 March 2007, 4,000 to 15,000 people (estimates vary significantly) protested the
Iraq War by marching from the
Lincoln Memorial
The Lincoln Memorial is a U.S. national memorial built to honor the 16th president of the United States, Abraham Lincoln. It is on the western end of the National Mall in Washington, D.C., across from the Washington Monument, and is in the ...
to the Pentagon's north parking lot.
September 11, 2001 attacks
On
September 11, 2001, coincidentally the 60th anniversary of the Pentagon's groundbreaking, five
al-Qaeda
Al-Qaeda (; , ) is an Islamic extremism, Islamic extremist organization composed of Salafist jihadists. Its members are mostly composed of Arab, Arabs, but also include other peoples. Al-Qaeda has mounted attacks on civilian and military ta ...
affiliated
hijackers took control of
American Airlines Flight 77
American Airlines Flight 77 was a scheduled American Airlines domestic transcontinental passenger flight from Washington Dulles International Airport in Dulles, Virginia, to Los Angeles International Airport in Los Angeles, California. The Boe ...
, ''en route'' from
Washington Dulles International Airport to
Los Angeles International Airport
Los Angeles International Airport , commonly referred to as LAX (with each letter pronounced individually), is the primary international airport serving Los Angeles, California and its surrounding metropolitan area. LAX is located in the W ...
, and deliberately crashed the
Boeing 757 airliner into the western side of the Pentagon at 9:37 am EDT as part of the
September 11 attacks. The impact of the plane severely damaged the outer ring of one wing of the building and caused its partial collapse. At the time of the attacks, the Pentagon was under renovation and many offices were unoccupied, resulting in fewer casualties. Only 800 of 4,500 people who would have been in the area were there because of the work.
[ Furthermore, the area hit, on the side of the Heliport façade, was the section best prepared for such an attack. The renovation there, improvements which resulted from the Oklahoma City bombing, had nearly been completed.]
It was the only area of the Pentagon with a sprinkler system, and it had been reconstructed with a web of steel columns and bars to withstand bomb blasts. The steel reinforcement, bolted together to form a continuous structure through all of the Pentagon's five floors, kept that section of the building from collapsing for 30 minutes—enough time for hundreds of people to crawl out to safety. The area struck by the plane also had blast-resistant windows— thick and each—that stayed intact during the crash and fire. It had fire doors that opened automatically and newly built exits that allowed people to get out.
Contractors already involved with the renovation were given the added task of rebuilding the sections damaged in the attacks. This additional project was named the " Phoenix Project" and was charged with having the outermost offices of the damaged section occupied by 11 September 2002.
When the damaged section of the Pentagon was repaired, a small indoor memorial and chapel were added at the point of impact. For the fifth anniversary of the September 11 attacks, a memorial of 184 beams of light shone up from the center courtyard of the Pentagon, one light for each victim of the attack. In addition, an American flag is hung each year on the side of the Pentagon damaged in the attacks, and the side of the building is illuminated at night with blue lights. After the attacks, plans were developed for an outdoor memorial, with construction underway in 2006. This Pentagon Memorial consists of a park on of land, containing 184 benches, one dedicated to each victim. The benches are aligned along the line of Flight 77 according to the victims' ages, from 3 to 71. The park opened to the public on 11 September 2008.
Gallery
File:Pentagon construction.jpg, View from northwest with construction underway, July 1942
File:The Pentagon US Department of Defense building.jpg, Southwesterly view (1998) with the Potomac River and Washington Monument in background
File:Aerial view of the Pentagon during rescue operations post-September 11 attack.JPEG, Aftermath of 9/11 attacks
File:Pentagon blue lights.jpg, 9/11 anniversary illumination, 2007
File:Pentagon Memorial-5089.jpg, Pentagon 9/11 Memorial
See also
*List of National Historic Landmarks in Virginia
This is a list of National Historic Landmarks in Virginia. There are currently 123 National Historic Landmark, National Historic Landmarks (NHLs), and 2 former NHLs.
Current landmarks
The National Historic Landmarks (NHLs) are widely distributed ...
* List of United States military bases
* National Register of Historic Places listings in Arlington County, Virginia
*The Octagon The Octagon may refer to:
*The Octagon, Christchurch, a former church in the central city of Christchurch, New Zealand
*The Octagon, Dunedin, the city centre of Dunedin, New Zealand
*The Octagon (Egypt), the headquarters of the Egyptian Ministry of ...
, headquarters of the Egyptian Ministry of Defense in the New Administrative Capital
* Pentagon Force Protection Agency
Notes
References
Citations
Sources
*
*
External links
The Pentagon website
(archived version)
''Popular Mechanics'', March 1943, ''"Army's Giant Five-by-Five"''
one of earliest World War II articles on the Pentagon
Pentagon Force Protection Agency
nbsp;– ''The Washington Post'', 26 May 2007
*
{{DEFAULTSORT:Pentagon
Military installations in Virginia
Military headquarters in the United States
Buildings and structures in Arlington County, Virginia
Government buildings completed in 1943
Government buildings on the National Register of Historic Places in Virginia
National Historic Landmarks in Virginia
National Register of Historic Places in Arlington County, Virginia
American Airlines Flight 77
Articles containing video clips
1943 establishments in Virginia
US
September 11 attacks