Editing Arlington National Cemetery (section)

==Memorials==
{{main|List of memorials and monuments at Arlington National Cemetery}}

===Tomb of the Unknown Soldier===
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{{Main|Tomb of the Unknown Soldier (Arlington National Cemetery)}}

The [[Tomb of the Unknown Soldier (Arlington)|Tomb of the Unknown Soldier]] stands on top of a hill overlooking Washington, D.C. One of the more well-attended sites at the cemetery, the tomb is made from Yule marble quarried in Colorado. It consists of seven pieces, with a total weight of 79 [[short ton]]s (72 [[metric ton]]s). The tomb was completed and opened to the public 9 April 1932, at a cost of $48,000.

Other unknown servicemen were later placed in crypts there, and it also became known as the Tomb of the Unknowns, though it has never been officially named. The soldiers entombed there are:
* Unknown Soldier of [[World War I]], entombed 11 November 1921; President [[Warren G. Harding]] presided
* Unknown Soldier of [[World War II]], interred 30 May 1958; President [[Dwight D. Eisenhower]] presided
* Unknown Soldier of the [[Korean War]], also interred 30 May 1958; President Dwight Eisenhower presided again, Vice President [[Richard Nixon]] acted as next of kin
* Unknown Soldier of the [[Vietnam War]], interred 28 May 1984; President [[Ronald Reagan]] presided. The remains of the Vietnam Unknown were disinterred, under the authority of President [[Bill Clinton]], on 14 May 1998, and were identified as those of Air Force first Lt. [[Michael Blassie|Michael J. Blassie]], whose family had them reinterred near their home in [[St. Louis, Missouri]]. It has been determined that the crypt at the Tomb of the Unknowns that contained the remains of the Vietnam Unknown will remain empty.

The Tomb of the Unknown Soldier has been perpetually guarded since 2 July 1937, by the U.S. Army. The [[3rd United States Infantry Regiment (TOG)|3rd U.S. Infantry Regiment]] ("The Old Guard") began guarding the Tomb on 6 April 1948. There is a meticulous routine that the guard follows when watching over the graves.<ref>{{cite web|archive-url=https://web.archive.org/web/20110925062923/http://www.arlingtoncemetery.mil/VisitorInformation/ChangingofTheGuard.aspx |archive-date=September 25, 2011 |url=http://www.arlingtoncemetery.mil/VisitorInformation/ChangingofTheGuard.aspx |title=The Changing of the Guard |location=Arlington County, Virginia |publisher=Arlington National Cemetery |access-date=January 21, 2012 |url-status=dead }}</ref> The Tomb Guard:
# Marches 21 steps southward down the black mat behind the Tomb
# Turns left, facing east for 21 seconds
# Turns left, facing north for 21 seconds
# Takes 21 steps down the mat
# Repeats the routine until the soldier is relieved of duty at the [[guard mounting|changing of the guard]]

After each turn, the Guard executes a sharp "shoulder-arms" movement to place the weapon on the shoulder closest to the visitors to signify that the Guard stands between the Tomb and any possible threat.

Twenty-one was chosen because it symbolizes the highest military honor that can be bestowed{{snd}}the [[21-gun salute#United States|21-gun salute]].

At each turn, the guard makes precise movements followed by a loud click of the heels as the soldier snaps them together. The guard is changed every half-hour during daylight in the summer, and every hour during daylight in the winter and every two hours at night (when the cemetery is closed to the public), regardless of weather conditions.

[[File:Arlington Amphitheater 1922 U.S. stamp.1.jpg|thumb|right|Arlington Amphitheater 1922 issue]]
A commemorative stamp was issued on 11 November 1922, the first anniversary of the first entombment picturing the Amphitheater. It encompasses the original Tomb of the Unknown Soldier. The remains of an unidentified American soldier from World War I were entombed on Armistice Day, 11 November 1921, later covered in 1931 by a more elaborate marble sarcophagus.<ref>Juell, Rod. "50-cent Arlington Amphitheater", Arago: people, postage & the post, National Postal Museum online, viewed March 12, 2014.</ref>

===Other memorials===
[[File:USS Maine Mast Memorial.jpg|thumb|The USS ''Maine'' Mast Memorial]]
There are several memorials on the grounds of the cemetery. However, due to the lack of space for burials and the large amount of space that memorials take up, the U.S. Army now requires a joint or concurrent resolution from Congress before it will place new memorials at Arlington.

Near the Tomb of the Unknowns stands the [[USS Maine Mast Memorial|USS ''Maine'' Mast Memorial]], which commemorates the 266 men who died aboard the [[USS Maine (ACR-1)|USS ''Maine'']]. The memorial is built around a [[mast (sailing)|mast]] salvaged from the ship's wreckage. The memorial served as the temporary resting place for two foreign heads of state or government who died in exile in the United States during World War II, [[Manuel L. Quezon]] of the Philippines and [[Ignacy Jan Paderewski]] of Poland.

The [[Space Shuttle]] ''[[Space Shuttle Challenger|Challenger]]'' Memorial was dedicated on 20 May 1986, in memory of the crew of flight [[STS-51-L]], who [[Space Shuttle Challenger disaster|died during launch]] on 28 January 1986. Transcribed on the back of the stone is the text of the [[John Gillespie Magee, Jr.]] poem "[[High Flight]]", which was quoted by then President Ronald Reagan when he addressed the disaster. Although many remains were identified and returned to the families for private burial, some were not, and were laid to rest under the marker. Two crew members, [[Dick Scobee]] and [[Michael J. Smith (astronaut)|Michael Smith]], are buried in Arlington. On 1 February 2004, [[NASA]] Administrator [[Sean O'Keefe]] dedicated a similar memorial to those who died when the Shuttle ''[[Space Shuttle Columbia|Columbia]]'' [[Space Shuttle Columbia disaster|broke apart during reentry]] on 1 February 2003.<ref name="NASA">{{cite web| title=Columbia Memorial Dedicated at Arlington| publisher=NASA| url=http://www.nasa.gov/columbia/home/F_04_Memorials.html| access-date=July 29, 2011| archive-url=https://web.archive.org/web/20110918002921/http://www.nasa.gov/columbia/home/F_04_Memorials.html| archive-date=September 18, 2011| url-status=live}}</ref> Astronauts [[Laurel Clark]], [[David M. Brown|David Brown]], and [[Michael P. Anderson|Michael Anderson]], who were killed in the ''Columbia'' disaster, are also buried in Arlington.

The Lockerbie Cairn is a memorial to the 270 killed in the bombing of [[Pan Am Flight 103]] over [[Lockerbie]], Scotland. The memorial is constructed of 270 stones, one for each person killed in the disaster. In section 64, a memorial to the 184 victims of the [[September 11 attacks|11 September attacks]] on the Pentagon was dedicated 11 September 2002. The memorial takes the shape of a pentagon, and lists the names of all the victims who were killed. Unidentified remains from the victims are buried beneath it.<ref name="Pentagon">{{cite news| title=Remains of Pentagon Attack Victims Buried at Arlington| url=https://www.defense.gov/News/News-Stories/id/43465/| work=American Forces Press Service| publisher=Department of Defense| author=Jim Garamone| date=September 12, 2002| access-date=July 27, 2011| archive-date=June 8, 2011| archive-url=https://web.archive.org/web/20110608235447/http://www.defense.gov/news/newsarticle.aspx?id=43465| url-status=live}}</ref>

On 25 June 1925, President [[Calvin Coolidge]] approved a request to erect a Commonwealth [[Cross of Sacrifice]] with the names of all the citizens of the United States who died fighting in the Canadian forces during World War I. The monument was dedicated 11 November 1927, and after the Korean War and World War II the names of US citizens who died in those conflicts were added.

In 2008, a bronze [[Braille flag]] was installed as a monument to blinded or blind veterans, service members, and other Americans after the passing of the H.R. 4169 American Braille Flag Memorial Act.<ref>{{cite web |title=Text of H.R. 4169 (110th): American Braille Flag Memorial Act (Referred to Senate Committee version) |url=https://www.govtrack.us/congress/bills/110/hr4169/text |website=GovTrack.us |language=en}}</ref><ref>{{cite web |title=GovInfo |url=https://www.gpo.gov/fdsys/pkg/BILLS-110hr4169eh/content-detail.html |website=www.govinfo.gov |language=en}}</ref>

The [[Laos Memorial]], or Lao Veterans of America memorial, dedicated to Lao and Hmong veterans who served with [[US Special Forces]] and [[CIA]] advisors during the Vietnam War, to defend the Royal [[Kingdom of Laos]] from the [[North Vietnamese invasion of Laos]], is located on Grant Avenue near the eternal flame memorial to U.S. President [[John F. Kennedy]].<ref>Smith, Philip, Lao Veterans of America, Inc. Washington, D.C. (May 15, 1997), http://www.laoveteransofamerica.org {{webarchive|url=https://web.archive.org/web/20161227015927/http://www.laoveteransofamerica.org/ |date=December 27, 2016 }}</ref>

In 2012, legislation began moving through Congress to approve a "Place of Remembrance" at the cemetery. The memorial will be an [[ossuary]] designed to contain fragments of remains which are unidentifiable through DNA analysis. The remains will be cremated before placement in the memorial.<ref>"Fast Track: 'Place of Remembrance' Planned for Arlington." ''Navy Times.'' June 25, 2012.</ref>