Crusaders from the Fourth Crusade broke through Constantinople’s walls and entered the great city.
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Rock Around The Clock by Bill Haley and His Comets was recorded.
The Battle of Fort Sumter in South Carolina between the United States and the Confederate States started the American Civil War.
The first Space Shuttle mission was launched.
The 'Twentieth Century Dinosaurs' exhibit opened at the Smithsonian Institution Museum of Natural History.
Israeli Knesset chose April 13 as the official Holocaust Remembrance Day.
