April 22

• 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 than was in the earlier treaty.
• 1836 - Texas Revolution: A day after the Battle of San Jacinto forces under Texan General Sam Houston capture Mexican General Antonio Lopez de Santa Anna.
• 1863 - American Civil War: Grierson's Raid begins - Troops under Union Colonel Benjamin Grierson attack central Mississippi.
• 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.
• 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 of 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.
• 1944 - World War II: Operation Persecution initiated - Allied forces land in the Hollandia area of New Guinea.
• 1945 - World War II: After learning that Soviet forces took Eberswalde without a fight, Adolf Hitler admits defeat in his underground bunker and states that suicide is his only recourse.
• 1954 - Red Scare: Senator Joseph McCarthy begins hearings investigating the United States Army for being "soft" on Communism.
• 1970 - First Earth Day celebrated.
• 1971 - John Kerry, dressed in combat fatigues, testifies on his views of the Vietnam War before the United States Senate Foreign Relations Committee
• 1972 - Vietnam War: Increased American bombing in Vietnam prompts antiwar protests in New York City, San Francisco, and Los Angeles.
• 1975 - Barbara Walters signs a five-year US$5 million contract with ABC, becoming the highest paid television newsperson.
• 1978 - The Blues Brothers make their first appearance on Saturday Night Live
• 1993 - In Washington, DC, the Holocaust Memorial Museum is dedicated.
• 1993 - Mosaic version 1.0 is released.
• 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 Elián González 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.
• 2004 - Two fuel trains collide in Ryongchon, North Korea killing up to 3000 people.

• 1451 - Isabella of Castile (d. 1504)
• 1550 - Edward de Vere, 17th Earl of Oxford, hereditary Lord Great Chamberlain of England (d. 1604)
• 1610 - Pope Alexander VIII (d. 1691)
• 1707 - Henry Fielding, author (d. 1754)
• 1724 - Immanuel Kant, philosopher (d. 1804)
• 1766 - Madame de Staël, author (d. 1817)
• 1812 - Solomon Caesar Malan, orientalist (d. 1894)
• 1840 - Odilon Redon, painter (d. 1916)
• 1870 (N.S.) - Vladimir Lenin, revolutionary, state leader, also Vladmir Ilyich Ulynanov (d. 1924)
• 1873 - Ellen Glasgow, Pulitzer Prize winning author
• 1876 - Robert Barany, Nobel Prize winner in medicine
• 1891 - Harold Jeffreys, astronomer (d. 1989)
• 1899 - Vladimir Nabokov, writer (d. 1977)
• 1904 - Robert Oppenheimer, physicist (d. 1967)
• 1906 - Prince Gustaf Adolf, Duke of Westrobothnia, second in line to the Swedish throne (d. 1946)
• 1914 - Jan de Hartog, writer (d. 2002)
• 1916 - Yehudi Menuhin, violinist (d. 1999)
• 1922 - Charles Mingus, musician (d. 1979)
• 1923 - Aaron Spelling, television producer, writer
• 1923 - Bettie Page, pin-up model
• 1926 - James Stirling, architect (d. 1992)
• 1936 - Glen Campbell, musician
• 1937 - Jack Nicholson, actor
• 1950 - Peter Frampton, musician
• 1951 - Tony Danza, actor
• 1952 or 1954 - Marilyn Chambers, erotic actress
• 1953 - Frank Netzel, Political Activist and Freedom Fighter
• 1959 - Ryan Stiles, actor
• 1975 - Greg Moore, race car driver (CART) (d. 1999)

• 536 - Pope Agapetus I
• 1896 - Thomas Meik, civil engineer (b. 1812)
• 1946 - Harlan F. Stone, Chief Justice of the United States
• 1951 - Horace St. John Kelly Donisthorpe, British Entomologist, Myrmecologist and Coleopterist (b. 1870)
• 1983 - Earl 'Fatha' Hines, musician
• 1984 - Ansel Adams, American photographer (b. 1902)
• 1988 - Irene Rich, actress
• 1994 - Richard Nixon, former President of the United States (b. 1913)
• 1996 - Erma Bombeck, humorist, writer (b. 1927)
• 2004 - Pat Tillman, American football player (b. 1976)

• Earth Day