Source: HistoryNet.com
1204: The Fourth Crusade sacks Constantinople.
1606: England adopts the Union Jack as its flag.
1877: The first catcher’s mask is used in a baseball game.
1917: The Canadian Corps mops up at Vimy Ridge, after capturing the stronghold April 9. The battle came at a price, with 3,600 Canadians killed and another 7,000 wounded.
1927: The British Cabinet comes out in favor of voting rights for women.
1955: Dr. Jonas Salk’s discovery of a polio vaccine is announced.
1961: Soviet Yuri Alexeyevich Gagarin becomes first man to orbit the Earth.
1963: Police use dogs and cattle prods on peaceful civil rights demonstrators in Birmingham, Alabama.
1966: Emmett Ashford becomes the first African-American major league umpire.
1967: House of Commons recommends making O Canada the national anthem. It will be proclaimed Canada's national anthem on July 1, 1980.
1980: Terry Fox dips his artificial leg into the Atlantic to start his cross-country 'Marathon of Hope'.