1827 - The Baltimore & Ohio Railroad became the first railroad incorporated for commercial transportation of people and freight.
1844 - Several people were killed aboard the USS Princeton when a 12-inch gun exploded.
1849 - Regular steamboat service to California via Cape Horn arrived in San Francisco for the first time. The SS California had left New York Harbor on October 6, 1848. The trip took 4 months and 21 days.
1861 - The U.S. territory of Colorado was organized.
1881 - Thomas Edison hired Samuel Insull as his private secretary.
1883 - The first vaudeville theater opened.
1885 - AT&T (American Telephone and Telegraph) was incorporated. The company was capitalized on only $100,000 and provided long distance service for American Bell.
1893 - Edward G. Acheson showed his patent for Carborundum.
1900 - In South Africa, British troops relieved Ladysmith, which had been under siege since November 2, 1899.
1911 - Thomas A. Edison, Inc. was organized.
1940 - The first televised basketball game was shown. The game featured Fordham University and the University of Pittsburgh from Madison Square Gardens in New York.
1948 - Bud Gartiser set a world record when he cleared the 50-yard low hurdles in 6.8 seconds.
1951 - A Senate committee issued a report that stated that there were at least two major crime syndicates in the U.S.
1953 - In a Cambridge University laboratory, scientists James D. Watson and Francis H.C. Crick discovered the double-helix structure of DNA.
1954 - In San Francisco "Birth of a Planet" was aired. It was the first American phase-contrast cinemicrography film to be presented on television.
1956 - A patent was issued to Forrester for a computer memory core.
1962 - The John Glenn for President club was formed by a group of Las Vegas republicans.
1974 - The U.S. and Egypt re-established diplomatic relations after a break of seven years.
1979 - Mr. Ed, the talking horse from the TV show "Mr. Ed", died.
1983 - "M*A*S*H" became the most watched television program in history when the final episode aired.
1986 - Swedish Prime Minister Olof Palme was assassinated in Stockholm.
1993 - U.S. Federal agents raided the compound of an armed religious cult in Waco, TX. The ATF had planned to arrest the leader of the Branch Davidians, David Koresh, on federal firearms charges. Four agents and six Davidians were killed and a 51-day standoff followed.
1994 - NATO made its first military strike when U.S. F-16 fighters shot down four Bosnian Serb warplanes in violation of a no-fly zone over central Bosnia.
1995 - The Denver International Airport opened after a 16-month delay.
1998 - Serbian police began a campaign to wipe out "terrorist gangs" in the Yugoslav province of Kosovo.
2001 - The Northwest region of the U.S., including the state of Washington, was hit by an earthquake that measured 6.9 on the Richter Scale. There were no deaths reported.
2002 - In Ahmadabad, India, Hindus set fire to homes in a Muslim neighborhood. At least 55 people were killed in the attack.
2002 - Sotheby's auction house announced that it had identified Peter Paul Reubens as the creator of the painting "The Massacre of the Innocents." The painting was previously thought to be by Jan van den Hoecke.
2002 - It was announced that John Madden would be replacing Dennis Miller on "Monday Night Football." Madden signed a four-year $20 million deal with ABC Sports.
2007 - NASA's New Horizons spacecraft made a gravitational slingshot against Jupiter to change the planned trajectory towards Pluto.
2013 - Benedict XVI resigned as pope. He was the first pope to resign since Gregory XII in 1415 and the first to resign voluntarily since Celestine V in 1294.