• 1500 - Portuguese navigator Pedro Álvares Cabral becomes the first European to sight Brazil.
• 1509 - Henry VIII accedes to the throne of England after the death of his father.
• 1529 - Treaty of Saragossa divides the eastern hemisphere between Spain and Portugal along a line 297.5 leagues or 17° east of the Moluccas.
• 1836 - Texas Revolution: A day after the Battle of San Jacinto forces under Texas General Sam Houston capture Mexican General Antonio López de Santa Anna.
• 1863 - American Civil War: Grierson's Raid begins – troops under Union Colonel Benjamin Grierson attack central Mississippi.
• 1864 - The U.S. Congress passes the Coinage Act which mandates that the inscription "In God We Trust" be placed on all coins minted as United States currency.
• 1889 - At high noon, thousands rush to claim land in the Land Run of 1889. Within hours the cities of Oklahoma City and Guthrie are formed with populations of at least 10,000.
• 1898 - Spanish-American War: The United States Navy begins a blockade of Cuban ports and the USS Nashville captures a Spanish merchant ship.
• 1912 - Pravda, the "voice" of the Communist Party of the Soviet Union, begins publication in Saint Petersburg.
• 1915 - The use of poison gas in World War I escalates when chlorine gas is released as a chemical weapon in the Second Battle of Ypres.
• 1930 - The United Kingdom, Japan and the United States sign the London Naval Treaty regulating submarine warfare and limiting shipbuilding.
• 1944 - World War II: Operation Persecution initiated – Allied forces land in the Hollandia (currently known as Jayapura) area of New Guinea.
• 1945 - World War II: Prisoners at the Jasenovac concentration camp revolt. 520 are killed and 80 escape.
• 1945 - World War II: Fuehrerbunker: After learning that Soviet forces have taken Eberswalde without a fight, Adolf Hitler admits defeat in his underground bunker and states that suicide is his only recourse.
• 1954 - Red Scare: Army-McCarthy Hearings begin.
• 1964 - The 1964-1965 New York World's Fair opens for its first season.
• 1970 - First Earth Day celebrated.
• 1972 - Vietnam War: Increased American bombing in Vietnam prompts antiwar protests in New York City, San Francisco, and Los Angeles.
• 1983 - The German magazine, Der Stern claims that Adolf Hitler's diaries were found in wreckage in East Germany.
• 1992 - In an explosion in Guadalajara, Mexico, 206 people are killed, nearly 500 injured and 15,000 left homeless.
• 1993 - The Holocaust Memorial Museum in Washington, DC is dedicated.
• 1993 - The web browser Mosaic version 1.0 is released.
• 1997 - Haouch Khemisti massacre in Algeria - 93 villagers killed.
• 1997 - The Japanese embassy hostage crisis ends in Lima, Peru.
• 1998 - Disney's Animal Kingdom opens at Walt Disney World near Orlando, Florida, United States.
• 2000 - In a pre-dawn raid, federal agents seize six-year-old Elián González from his relatives' home in Miami, Florida.
• 2000 - The Big Number Change takes place in the United Kingdom.
• 2004 - Two fuel trains collide in Ryongchon, North Korea, killing up to 150 people.
• 2006 - 243 people are injured in pro-democracy protest in Nepal after Nepali security forces open fire on protesters against King Gyanendra.
• 2006 - Four Canadian soldiers are killed 75 kilometers north of Kandahar, Afghanistan by a roadside bomb planted by Taliban militants, the worst single day combat loss for the Canadian army since the Korean War.

Births