1496 – King Henry VII of England issues letters patent to John Cabot and his sons, authorizing them to explore unknown lands.
1770 – Boston Massacre. Five Americans, including Crispus Attucks, are fatally shot by British troops in an event that would contribute to the outbreak of the Revolutionary War.
1836 – Samuel Colt patents the first production-model revolver, the .34 caliber.
1933 – President Franklin D. Roosevelt declares a “bank holiday,” closing all U.S. banks and freezing all financial transactions.
1946 – Winston Churchill coins the phrase “Iron Curtain” in his speech at Westminster College, Missouri.
1953 – Joseph Stalin dies in Moscow after suffering a stroke.
1970 – The Treaty on the Non-Proliferation of Nuclear Weapons goes into effect after ratification by 43 nations.