Louis Pasteur performed his first pasteurization tests. (1864) Pasteur and Claude Bernard performed their first experiments with pasteurization on this day, intending to use it to preserve beer and wine. The process, which kills a variety of microbes and bacteria in liquids, is now used to sterilize almost all milk.
The Columbine school massacre occurred. (1999) The US was shocked by the high school killings in which two boys killed 13 people and injured more than 20 others before killing themselves. It was the fourth deadliest school shooting in US history, and led to a lot of discussion about gun control and violent youth.
The Vitaphone sound process was announced. (1926)Vitaphone was a collaboration between Warner Brothers and Western Electric used in over 1,000 short films. It is considered the most successful sound-on-disc process, a method in which a movie was filmed with the sound recorded onto records, which were then played simultaneously with the movie in theaters.
Marie and Pierre Curie isolated radium chloride. (1902) It was the first type of radium that the Curies isolated, and is still used to extract radium from pitchblende as well as in the production of radon gas, a cancer treatment.
The Murders in the Rue Morgue was published. (1841) Often considered the first mystery story, The Murders in the Rue Morgue by Edgar Allen Poe focused on the analytical powers of Auguste Dupin, a character who influenced the creation of both Sherlock Holmes and Hercule Poirot.
The Ku Klux Act was passed. (1871) The Civil Rights Act of 1871, also known as the Ku Klux Act, was put in place to protect African-American people from abuses such as those perpetrated by the Ku Klux Klan. Though largely ineffective in the beginning, the act has been used in several major court cases since then.
President McKinley signed a joint resolution demanding Spain leave Cuba. (1898) Tensions had been mounting between the US and Spain ever since the USS Maine had blown up about a month earlier. Despite McKinley's efforts to keep neutral, public opinion was heavily against Spain, which considered the resolution a declaration of war.
RCA demonstrated its new electron microscope. (1940) The company was among the first to develop the electron microscope, which remains widely used in many forms of scientific research today.
Adolf Hitler was born. (1889) The future Führer was born in Austria on this day as the fourth of six children. Often labeled as one of the most evil men in history, Hitler actually thought of becoming a priest in his early life.
Danica Patrick became the first woman to win an Indy race. (2008) Patrick's win was a landmark in a largely male-dominated sport, and she is considered the first woman to win in a top-tier American race.