1960 – Togo gains independence from French-administered UN trusteeship.
1961 – Sierra Leone is granted its independence from the United Kingdom, with Milton Margai as the first Prime Minister.
1967 – Expo 67 officially opens in Montreal, Canada with a large opening ceremony broadcast around the world. It opens to the public the next day.
1974 – Ten thousand march in Washington, D.C., calling for the impeachment of U.S. President Richard Nixon
1977 – Twenty-eight people are killed in the Guatemala City air disaster.
1978 – Former United States President Nixon aide John D. Ehrlichman is released from an Arizona prison after serving 18 months for Watergate-related crimes.
1981 – Xerox PARC introduces the computer mouse.
1986 – The city of Pripyat as well as the surrounding areas are evacuated due to Chernobyl disaster.
1987 – The U.S. Department of Justice bars Austrian President Kurt Waldheim from entering the United States, saying he had aided in the deportation and execution of thousands of Jews and others as a German Army officer during World War II.
1989 – The April 27 demonstrations, student-led protests responding to the April 26 Editorial, during the Tiananmen Square protests of 1989.
1992 – The Federal Republic of Yugoslavia, comprising Serbia and Montenegro, is proclaimed.
1992 – Betty Boothroyd becomes the first woman to be elected Speaker of the British House of Commons in its 700-year history.
1992 – The Russian Federation and 12 other former Soviet republics become members of the International Monetary Fund and the World Bank.
1993 – All members of the Zambia national football team lose their lives in a plane crash off Libreville, Gabon en route to Dakar, Senegal to play a 1994 FIFA World
Cup qualifying match against Senegal.
1994 – South African general election: The first democratic general election in South Africa, in which black citizens could vote. The Interim Constitution comes into force.
1996 – The 1996 Lebanon war ends.
2002 – The last successful telemetry from the NASA space probe Pioneer 10.
2005 – The superjumbo jet aircraft Airbus A380 makes its first flight from Toulouse, France.
2006 – Construction begins on the Freedom Tower (later renamed One World Trade Center) in New York City.
2007 – Estonian authorities remove the Bronze Soldier, a Soviet Red Army war memorial in Tallinn, amid political controversy with Russia.
2011 – The April 25–28 tornado outbreak devastates parts of the Southeastern United States, especially the states of Alabama, Mississippi, Georgia, and Tennessee. Two hundred five tornadoes touched down on April 27 alone, killing more than 300 and injuring hundreds more.
2011 – United Nations Security Council Resolution 1978 and 1979 are adopted.
2012 – At least four explosions hit the Ukrainian city of Dnipropetrovsk with at least 27 people injured.
2014 – Popes John XXIII and John Paul II are declared saints in the first papal canonization since 1954.
2014 – A tornado outbreak over much of the eastern United States kills 35 people
