Today:
1740: Maria Theresa ascends to the Habsburg throne in Austria, Hungary, and Bohemia.
1774: The First Continental Congress creates the Continental Association, which called for a trade boycott against Great Britain.
1803: The U.S. Senate ratifies the treaty for the Louisiana Purchase, doubling the size of the country.
1818: The United States and the United Kingdom sign the Convention of 1818, which sets the border between the U.S. and Canada at the 49th parallel.
1935: The Long March, a massive military retreat by the Red Armies of the Chinese Communist Party, comes to an end.
1944: General Douglas MacArthur lands on the island of Leyte, fulfilling his promise, “I shall return,” to the Philippines during World War II.
1947: The House Un-American Activities Committee begins its hearings into alleged Communist infiltration within the Hollywood film industry.
1968: Former U.S. First Lady Jacqueline Kennedy marries Greek shipping tycoon Aristotle Onassis.
1973: The Sydney Opera House is officially opened by Queen Elizabeth II in Sydney, Australia.
2011: Libyan leader Muammar Gaddafi is captured and killed by rebel forces in his hometown of Sirte.