1993 – Bureau of Alcohol, Tobacco and Firearms agents raid the Branch Davidian church in Waco, Texas with a warrant to arrest the group's leader David Koresh. Four BATF agents and five Davidians die in the initial raid, starting a 51-day standoff.

1983 – The final episode of M*A*S*H airs, with almost 106 million viewers. It still holds the record for the highest viewership of a season finale.

1953 – James Watson and Francis Crick announce to friends that they have determined the chemical structure of DNA; the formal announcement takes place on April 25 following publication in April's Nature (pub. April 2).

1928 – C. V. Raman discovers Raman scattering.



Oh... raman. Sorry. 

1525 – The Aztec king Cuauhtémoc is executed by Hernán Cortés's forces.

1942 – The Battle of Los Angeles, one of the largest documented UFO sightings in history; the event lasted into the early hours of February 25.

 aflanigan wrote: 

 Red_Dragon wrote: 
Are you sure?

1954 – The first mass inoculation of children against polio with the Salk vaccine begins in Pittsburgh.

1927 – German theoretical physicist Werner Heisenberg writes a letter to fellow physicist Wolfgang Pauli, in which he describes his uncertainty principle for the first time.

1896 – The Tootsie Roll is invented.

2013 – The smallest extrasolar planet, Kepler-37b is discovered.

1986 – The Soviet Union launches its Mir spacecraft. Remaining in orbit for 15 years, it is occupied for ten of those years.

1965 – Ranger 8 crashes into the Moon after a successful mission of photographing possible landing sites for the Apollo program astronauts.

1962 – Mercury program: While aboard Friendship 7, John Glenn becomes the first American to orbit the earth, making three orbits in four hours, 55 minutes.

1872 – In New York City the Metropolitan Museum of Art opens.

1985 - Prodigal_SOB signs a thirty year mortgage on his current abode.  Amazing what a little inertia and a total lack of ambition can accomplish.

 

1809 — Charles Darwin and Abraham Lincoln are born.

1996 – The IBM supercomputer Deep Blue defeats Garry Kasparov in chess for the first time.

1962 – Roy Lichtenstein's first solo exhibition opened, and it included Look Mickey, which featured his first employment of Ben-Day dots, speech balloons and comic imagery sourcing, all of which he is now known for.