1763 – Charles Mason & Jeremiah Dixon begin surveying Mason-Dixon Line between Pennsylvania & Maryland.
1791 – 1st Catholic college in US, Georgetown, opens.
1864 – Union Major General Sherman leaves Atlanta on his “March to the Sea”
1869 – Free postal delivery formally inaugurated.
1904 – King C. Gillette patents the Gillette razor blade.
1919 – US Senate 1st invokes cloture to end a filibuster (Versailles Treaty)
1937 – First US congressional session in air-conditioned chambers.
1939 – The first unemployment compensation law, under the Social Security Act, that of the District of Columbia, was approved for grants by the Social Security Board.
1940 – 1st 75,000 men called to armed forces duty during peacetime.
1945 – The rules are revised for election of modern players to the Hall of Fame.
1954 – 1st regularly scheduled commercial flights over North Pole begins.
1959 – Richard “Dick” Hickock and Perry Smith murder four members of the Clutter Family at their farm outside Holcomb, Kansas (subject of Truman Capote book in Cold Blood)
1969 – An estimated 2 million people take part in the Vietnam War Moratorium demonstration across the United States.
1969- Wendy’s Hamburgers, American fast food restaurant chains founded by Dave Thomas opens in Columbus, Ohio.
1975 – “Mammas Don’t Let Your Babies Grow Up to be Cowboys” single released by Ed Bruce.
1979 – A package from the Unabomber Ted Kaczynski begins smoking in the cargo hold of a flight from Chicago to Washington, forcing the plane to land to make an emergency landing.
1979 – Iran cancels all contracts with U.S. oil companies.
1987 – 28 of 82 aboard Continental Airlines DC-9, die in crash in Denver.
1991 – Dow Jones average drops 120.31 points (5th largest dive)
2012 – Deep Horizon Oil Spill: BP settles for $4.5 Billion.
2013 – Sony launches the PlayStation Four, selling one million units on the first day.