Editing 1820 (section)

=== January–March ===
*[[January 1]] – A constitutionalist military insurrection at [[Cádiz]] leads to the summoning of the Spanish Parliament to meet on March 7, becoming the nominal beginning of the "[[Trienio Liberal]]" in [[History of Spain (1814–73)|Spain]].<ref>{{cite book|author=Miguel A López-Morell|title=The House of Rothschild in Spain, 1812–1941|url=https://books.google.com/books?id=XOYFgUAxnkIC&pg=PT46|date=28 June 2013|publisher=Ashgate Publishing, Ltd.|isbn=978-1-4724-0424-4|pages=46}}</ref>
*[[January 8]] – The [[General Maritime Treaty of 1820]], officially the "General Treaty for the Cessation of Plunder and Piracy by Land and Sea, dated February 5, 1820") is signed between the sheikhs of [[Abu Dhabi]], [[Sharjah (emirate)|Sharjah]], [[Ajman]], [[Umm al-Quwain]] and [[Ras Al Khaimah]] (later constituents of the [[Trucial States]]) in the [[Arabian Peninsula]] and the United Kingdom.<ref>{{Cite book|last=Lorimer|first=John|title=Gazetteer of the Persian Gulf|publisher=British Government|location=Bombay|year=1915}}</ref>
*[[January 27]] ([[Old Style and New Style dates|NS]], January 15 OS) – An [[Imperial Russian Navy]] expedition, led by [[Fabian Gottlieb von Bellingshausen]] in ''[[Vostok (sloop-of-war)|Vostok]]'' with [[Mikhail Petrovich Lazarev]], sights the [[Antarctic ice sheet]].<ref name=Jones>{{cite book|first=A. G. E.|last=Jones|year=1982|title=Antarctica Observed: who discovered the Antarctic Continent?|publisher=Caedmon of Whitby|isbn=0-905355-25-3}}</ref>
*[[January 29]] – [[George IV of the United Kingdom]] becomes the new British monarch upon the death his father [[George III of the United Kingdom|King George III]] after 59 years on the throne. The elder George's death ends the 9-year period known as the [[British Regency]]. 
*[[January 30]] – British [[Royal Navy]] captain [[Edward Bransfield]], an Irishman,  becomes the first person to positively identify [[Antarctica]] as a land mass.<ref name=Jones/>
*[[February 6]]
** [[Capture of Valdivia]]: [[Thomas Cochrane, 10th Earl of Dundonald|Lord Cochrane]] occupies [[Valdivia]] in the name of the Republic of [[Chile]].
** A group of 86 free [[African American]] colonists sail from New York City to [[Freetown, Sierra Leone]], with a goal of creating a home for freed American slaves, to be called "[[Liberia]]".
*[[February 14]] – Emperor [[Minh Mạng]] starts to rule in [[Vietnam]].
*[[February 20]] – A revolt begins against the Spanish crown in [[Santa María Chiquimula]] (now in [[Guatemala]]).<ref>{{cite book|author=William George Lovell|title=Conquest and Survival in Colonial Guatemala: A Historical Geography of the Cuchumatán Highlands, 1500-1821|url=https://books.google.com/books?id=05wSqQiu52MC&pg=PA116|year=2005|publisher=McGill-Queen's Press - MQUP|isbn=978-0-7735-2741-6|pages=116}}</ref>
*[[February 23]] – The [[Cato Street Conspiracy]], a plot to assassinate Britain's Prime Minister, [[Robert Jenkinson, 2nd Earl of Liverpool|Lord Liverpool]], and his [[Liverpool ministry|Cabinet]] is thwarted when police in [[London]] arrest 13 plotters after being warned by an informant.<ref name="Ewald1868">{{cite book|author=Alexander Charles Ewald|title=The Last Century of Universal History: A Reference Book, Containing an Annotated Table of Chronology, Lists of Contemporary Sovereigns, a Dictionary of Battles and Sieges, and Biographical Notes of Eminent In-dividuals. From 1767 to 1867|url=https://books.google.com/books?id=flkQAAAAYAAJ&pg=PA67|year=1868|publisher=F. Warne & Company|pages=67}}</ref>
*[[March 3]] – A fire in [[Guangzhou]] in China burns 15,000 houses and kills an undetermined number of people.<ref name=Fires>"Fires, Great", in ''The Insurance Cyclopeadia: Being an Historical Treasury of Events and Circumstances Connected with the Origin and Progress of Insurance'', Cornelius Walford, ed. (C. and E. Layton, 1876) pp69</ref>
*[[March 3]] and [[March 6|6]] – The [[Missouri Compromise]] becomes law, allowing admission of [[Missouri]] and [[Maine]], [[slave and free states]] respectively, as [[U.S. state]]s.
*[[March 9]] – King [[Ferdinand VII of Spain]] accepts the new constitution, beginning the ''[[Trienio Liberal]]''.
*[[March 10]] – The [[Royal Astronomical Society|Astronomical Society of London]] is founded.
*[[March 15]] – [[Maine]] is admitted as the 23rd [[U.S. state]].
*[[March 26]] – [[Joseph Smith]], founder of the [[Latter Day Saint movement]], receives his [[First Vision]] in [[Palmyra (town), New York|Palmyra, New York]].<ref>Lefgren, J. C. (October 2002). "Oh, How Lovely Was the Morning: Sun 26 Mar 1820?". ''Meridian Magazine''. (available at http://www.johnpratt.com/items/docs/lds/meridian/2002/vision.html)</ref>
*[[March 28]] – An attempted [[coup d'état]] against [[Paraguayan]] dictator [[José Gaspar Rodríguez de Francia]] fails after a plot by [[Fulgencio Yegros]] and [[Pedro Juan Caballero (politician)|Pedro Juan Caballero]].