Editing March 21 (section)

===1901–present===
*[[1918]] &ndash; [[World War I]]: The first phase of the [[German spring offensive]], [[Operation Michael]], begins.
*[[1919]] &ndash; The [[Hungarian Soviet Republic]] is established becoming the first [[Communism|Communist]] government to be formed in Europe after the [[October Revolution]] in [[Russian Empire|Russia]].
*[[1921]] &ndash; The [[New Economic Policy]] is implemented by the [[Bolshevik]] Party in response to the economic failure as a result of [[war communism]].
*[[1925]] &ndash; The [[Butler Act]] prohibits the teaching of [[human evolution]] in [[Tennessee]].
*  1925   &ndash; [[Syngman Rhee]] is removed from office after being [[Impeachment|impeached]] as the President of the [[Provisional Government of the Republic of Korea]].
*  1925   &ndash; Ravel's opera ''[[L'enfant et les sortilèges]]'', to a libretto by [[Colette]], is premiered at the [[Opéra de Monte-Carlo]].<ref>[http://www.laphil.com/philpedia/music/lenfant-et-les-sortileges-maurice-ravel ''L'Enfant et les sortilèges'' - Details] by McLellan, Joe; LA Philharmonic. {{webarchive|url=https://web.archive.org/web/20171230104847/https://www.laphil.com/philpedia/music/lenfant-et-les-sortileges-maurice-ravel |date=30 December 2017}}</ref>
*[[1928]] &ndash; [[Charles Lindbergh]] is presented with the [[Medal of Honor]] for the first solo trans-Atlantic flight.
*[[1934]] &ndash; The landmark [[Australian Eastern Mission]] led by [[John Greig Latham|John Latham]] departs on its three-month tour of East and South-East Asia.<ref>{{cite book|first=David|last=Bird|chapter=The Genesis of Australian Appeasement – The 'Australian Eastern Mission' of 1934 and its Aftermath|title=J. A. Lyons, The Tame Tasmanian: Appeasement and Rearmament in Australia, 1932–39|year=2008|publisher=Australian Scholarly Publishing|isbn=9781740971577|pages=60–93}}</ref>
*[[1935]] &ndash; [[List of monarchs of Persia|Shah of Iran]] [[Reza Shah|Reza Shah Pahlavi]] formally asks the international community to call [[Iran|Persia]] by its native name, ''[[Name of Iran|Iran]]''.
*[[1937]] &ndash; [[Ponce massacre]]: Nineteen unarmed civilians in [[Ponce, Puerto Rico]] are gunned down by police in a terrorist attack ordered by the US-appointed Governor, [[Blanton Winship]].
*[[1943]] &ndash; [[Wehrmacht]] officer [[Rudolf-Christoph von Gersdorff|Rudolf von Gersdorff]] plots to assassinate [[Adolf Hitler]] by using a suicide bomb, but the plan falls through; von Gersdorff is able to defuse the bomb in time and avoid suspicion.
*[[1945]] &ndash; [[World War II]]: British troops liberate [[Mandalay]], [[Burma]].
*  1945   &ndash; World War II: [[Operation Carthage]]: [[Royal Air Force]] planes bomb [[Gestapo]] headquarters in [[Copenhagen]], Denmark. They also accidentally hit a school, killing 125 civilians.
*  1945   &ndash; World War II: [[Kingdom of Bulgaria|Bulgaria]] and the [[Soviet Union]] successfully complete their defense of the north bank of the [[Drava]] River as the [[Battle of the Transdanubian Hills]] concludes.
*[[1946]] &ndash; The [[Los Angeles Rams]] sign [[Kenny Washington (American football)|Kenny Washington]], making him the first [[African American]] [[Black players in professional American football|player]] in professional [[American football]] since 1933.
*[[1952]] &ndash; [[Alan Freed]] presents the [[Moondog Coronation Ball]], the first [[rock and roll]] concert, in [[Cleveland, Ohio]].
*[[1960]] &ndash; [[Apartheid]]: [[Sharpeville massacre]], South Africa: Police open fire on a group of black South African demonstrators, killing 69 and wounding 180.
*[[1963]] &ndash; [[Alcatraz Federal Penitentiary]] closes.
*[[1965]] &ndash; [[Ranger program]]: [[NASA]] launches [[Ranger 9]], the last in a series of uncrewed lunar [[space probe]]s.
*  1965   &ndash; [[Martin Luther King Jr.]] leads 3,200 people on the start of the third and finally successful [[Selma to Montgomery marches|civil rights march]] from [[Selma, Alabama|Selma]] to [[Montgomery, Alabama]].
*[[1968]] &ndash; [[Battle of Karameh]] in [[Jordan]] between the [[Israel Defense Forces]] and the combined forces of the [[Jordanian Armed Forces]] and [[PLO]].
*[[1970]] &ndash; The first [[Earth Day]] proclamation is issued by [[Joseph Alioto]], [[Mayor of San Francisco]].
*  1970   &ndash; [[San Diego Comic-Con]], the largest [[Comic book convention|pop and culture festival]] in the world, hosts its inaugural event.<ref name="bbc">{{cite news |date=November 25, 2009 |title=Comic-Con co-creator Ken Krueger dies |work=[[BBC News]] |url=http://news.bbc.co.uk/2/hi/entertainment/8379221.stm |url-status=live |access-date=January 7, 2012 |archive-url=https://web.archive.org/web/20160304000150/http://news.bbc.co.uk/2/hi/entertainment/8379221.stm |archive-date=March 4, 2016}}</ref>
*[[1980]] &ndash; [[Cold War]]: American President [[Jimmy Carter]] announces a United States [[1980 Summer Olympics boycott|boycott]] of the [[1980 Summer Olympics]] in [[Moscow]] to protest the [[Soviet–Afghan War]].
*[[1983]] &ndash; The first cases of the [[1983 West Bank fainting epidemic]] begin; [[Israel]]is and [[State of Palestine|Palestinians]] accuse each other of poison gas, but the cause is later determined mostly to be [[psychosomatic]].
*[[1985]] &ndash; Canadian [[paraplegic]] athlete and humanitarian [[Rick Hansen]] begins his [[circumnavigation]] of the globe in a wheelchair in the name of [[spinal cord]] injury medical research.<ref>{{cite web |url=https://www.rickhansen.com/about-rick/ricks-story |website=Rick Hansen Foundation - Rick's Story |access-date=2 April 2025 |title=Rick's Story &#124; Rick Hansen Foundation }}</ref>
*[[1986]] &ndash; [[Debi Thomas]] became the first African American to win the [[World Figure Skating Championships]].
*[[1989]] &ndash; [[Transbrasil Flight 801]] crashes into a [[slum]] near [[São Paulo/Guarulhos International Airport]], killing 25 people.<ref>{{Cite web |last=Ranter |first=Harro |title=ASN Aircraft accident Boeing 707-349C PT-TCS São Paulo-Guarulhos International Airport, SP (GRU) |url=https://aviation-safety.net/database/record.php?id=19890321-0 |access-date=2022-03-20 |website=aviation-safety.net |publisher=[[Aviation Safety Network]]}}</ref>
*[[1990]] &ndash; [[Namibia]] becomes independent after 75 years of [[South Africa]]n rule.
*[[1994]] &ndash; The [[United Nations Framework Convention on Climate Change]] enters into force.
*[[1999]] &ndash; [[Bertrand Piccard]] and [[Brian Jones (aeronaut)|Brian Jones]] become the first to [[Circumnavigation|circumnavigate]] the Earth in a [[hot air balloon]].
*[[2000]] &ndash; [[Pope John Paul II]] makes his first ever [[Roman Pontifical|pontifical]] visit to [[Israel]].
*[[2006]] &ndash; The [[social media]] site [[Twitter]] (now officially named X) is founded.
*[[2019]] &ndash; The [[2019 Xiangshui chemical plant explosion]] occurs, killing at least 47 people and injuring 640 others.<ref>{{cite news|title=Devastation at blast site after China chemical plant explosion leaves 47 dead, 640 injured|url=https://www.scmp.com/news/china/society/article/3002772/jiangsu-chemical-plant-explosion-death-toll-reaches-44-32|access-date=2019-03-23|newspaper=South China Morning Post}}</ref>
*[[2022]] &ndash; [[China Eastern Airlines Flight 5735]] crashes in [[Guangxi]], China, killing 132 people.<ref>{{cite web |last1=Chang |first1=Wayne |title=Chinese airliner carrying 132 people crashes in southern Guangxi region |url=https://www.cnn.com/2022/03/21/china/china-plane-crash-guangxi-intl-hnk/index.html |website=CNN |date=21 March 2022 |access-date=23 March 2022}}</ref>