1497 Portuguese explorer Vasco de Gama became the first navigator to sail around the Cape of Good Hope in his search for a sea route to India.
1718 Edward Teach, better known as Blackbeard the pirate, was killed off the east coast of North America.
1842 Mount St. Helens in Washington state erupted. Ash fallout reached as far as 48 mi away.
1906 "S-O-S" was adopted as a distress signal at the International Radio Telegraphic Convention in Berlin.
1943 President Franklin Roosevelt, British prime minister Winston Churchill, and Chinese leader Chiang Kai-shek met in Cairo to discuss measures for defeating Japan
1963 President John F. Kennedy was assassinated while riding in a motorcade in Dallas.
1990 Margaret Thatcher announced her resignation as prime minister of the United Kingdom.