On this day in history

328: The official opening of Constantine's Bridge built over the Danube.
1610: John Guy sets sail from Bristol with 39 other colonists for Newfoundland.
1687: Isaac Newton publishes Philosophiæ Naturalis Principia Mathematica outlining laws of motion and universal gravitation.
1841: Thomas Cook opens first travel agency.
1865: US Secret Service begins operating under the Treasury Department.
1919: Red Sox Babe Ruth hits two HRs in a game for the first of 72 times.
1937: Spam, the luncheon meat, is introduced into the market by the Hormel Foods Corporation.
1942: Ian Fleming, author of James Bond fame, graduates from a training school for spies in Canada.
1945: The liberation of the Philippines is declared.
1946: The bikini goes on sale after debuting during an outdoor fashion show at the Molitor Pool in Paris, France.
1950: American and North Korean forces clash in the Battle of Osan.
1954: The BBC broadcasts its first television news bulletin.
1954: Elvis Presley records his first single, "That's All Right," at Sun Records in Memphis, Tennessee.
1971: The twenty-sixth amendment to the United States Constitution, which lowers the voting age from 21 to 18 years, is formally certified by President Richard Nixon.
1975: Arthur Ashe becomes the first black man to win the Wimbledon singles title.
1981: The AIDS epidemic officially begins when US Centers for Disease Control reports on pneumonia affecting five homosexual men in Los Angeles.
1989: Oliver North is sentenced to a three-year suspended prison term, two years’ probation, $150,000 in fines and 1,200 hours community service for his involvement in the Iran–Contra affair. His convictions are later overturned.
1994: Amazon.com founded by Jeff Bezos.
1996: Dolly the sheep becomes the first mammal cloned from an adult cell.