April 15 - Jackie Robinson, an African-American, takes the field at first base for the Brooklyn Dodgers major-league baseball team, breaking that sport's color line.
July 29 - After being shut off on November 9, 1946 for a refurbishment, ENIAC, one of the world's first digital computers, is turned on after a memory upgrade. It will remain in continuous operation until October 2, 1955.
August 7 - Thor Heyerdahl's balsa wood raft the Kon-Tiki, smashes into the reef at Raroia in the Tuamotu Islands after a 101 day 4,300 mile journey across the Pacific Ocean proving that pre-historic peoples could have traveled from South America.
August 14 - Pakistan gains indepdence from the British Empire. While the transition is officially at midnight on this day, Pakistan celebrates it's indepdence on August 14 compared to India on the 15th.
May 7 - Kraft Television Theater premieres on NBC, the first regularly scheduled drama series on a network.
September 30 - The opening game of the World Series is the first World Series game to be telecast. The 1947 World Series brought in an estimated 3.9 million people, becoming television's first mass audience.
October 5 - The first presidential address is telecast from the White House. President Truman speaks about the world food crisis.