April 22 is the 112th day of the year in the Gregorian calendar (113th in leap years). There are 253 days remaining.
- 1056 - Observation of a supernova in the Crab nebula.
- 1500 - Portuguese navigator Pedro Alvares Cabral becomes the first European to sight Brazil.
- 1509 - Henry VIII ascends to the throne of England after the death of his father.
- 1529 - Treaty of Saragossa divides the western hemisphere between Spain and Portugal that the dividing line should lay 297.5 leagues west of the Moluccas. Spain gets monetary compensation in return for giving Portugal more territory that was in the earlier treaty.
- 1864 - The United States Congress passes the Coinage Act of 1864[?] which mandates that the inscription "In God We Trust" needs to be placed on all coins minted as United States currency.
- 1889 - Oklahoma land rush[?]: President Benjamin Harrison opens Oklahoma to white settlement; Land rush[?] begins.
- 1898 - Spanish-American War: The United States Navy begins a blockade[?] of Cuban ports and the USS Nashville captures a Spanish merchant ship.
- 1914 - Baltimore Orioles' Babe Ruth, age 19, pitches his first professional game.
- 1915 - World War I: Second Battle Ypres[?] - German troops introduce poison gas at Ypres, Belgium.
- 1930 - The United Kingdom, Japan and the United States sign the London Naval Treaty regulating submarine warfare and limiting shipbuilding.
- 1943 - Albert Hofmann writes his first report about the hallucinogenic properties of LSD.
- 1954 - Senator Joseph McCarthy begins hearings investigating the United States Army for being "soft" on Communism.
- 1970 - First Earth Day celebrated
- 1978 - The Blues Brothers make their first appearance on Saturday Night Live
- 1993 - In Washington, DC, the Holocaust Memorial Museum[?] is dedicated.
- 1993 - release of Mosaic version 1.0
- 1997 - A 126-day hostage crisis at the residence of the Japanese ambassador in Lima, Peru ends after government commandos storm and capture the building rescuing 71 hostages. One hostage dies of a heart attack, two soldiers are killed from rebel fire and all 14 rebels were slain.
- 2000 - In a predawn raid, federal agents seize six-year old Elian Gonzalez from his relatives' home in Miami, Florida and fly him to his Cuban father in Washington, DC ending one of the most publicized custody battles in US history.
- 1451 - Isabella of Castile
- 1550 - Edward de Vere, 17th Earl of Oxford, hereditary Lord Great Chamberlain of England[?] (+ 1604)
- 1707 - Henry Fielding, author (+ 1754)
- 1724 - Immanuel Kant, philosopher (+ 1804)
- 1766 - Madame de StaŽl, author (+ 1817)
- 1840 - Odilon Redon, painter (+ 1916)
- 1870 (N.S.) - Vladimir Lenin, revolutionary, state leader (+ 1924)
- 1873 - Ellen Glasgow[?], Pulitzer Prize winning author
- 1891 - Harold Jeffreys[?], astronomer (+ 1989)
- 1899 - Vladimir Nabokov, writer (+ 1977)
- 1904 - Robert Oppenheimer, physicist (+ 1967)
- 1914 - Jan de Hartog[?], writer (+ 2002)
- 1916 - Yehudi Menuhin, violinist (+ 1999)
- 1922 - Charles Mingus, musician (+ 1979)
- 1922 - Sir Kingsley Amis, English novelist (+ 1995)
- 1923 - Aaron Spelling[?], television producer, writer
- 1923 - Bettie Page, pinup[?] model
- 1926 - James Stirling, architect (+ 1992)
- 1936 - Glen Campbell, musician
- 1937 - Jack Nicholson, actor
- 1950 - Peter Frampton, musician
- 1952 or 1954 - Marilyn Chambers, erotic actress
- 1953 - Frank Netzel[?] Political Activist and Freedom Fighter
April 21 - April 23 - March 22 - May 22 -- listing of all days
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