- The human genome was mapped. (2003) The Human Genome Project was completed on this day after over 20 years of work. The sequence of human genetic code was 99 percent mapped to a 99.99 percent accuracy.
- President Lincoln was assassinated. (1865) Lincoln was shot while attending a comedy at Ford's Theater only five days after Robert E. Lee surrendered, essentially ending the Civil War. His assassin, John Wilkes Booth, was caught almost immediately, and later hanged along with several co-conspirators.
- President Truman received the NSC-68 report. (1950) The report was a comprehensive analysis of America's foreign policy strategies done by the Defense Department, the CIA, and the State Department, and went on to form much of America's foreign policy during the Cold War.
- The Titanic hit an iceberg and began to sink. (1912) The massive luxury liner stayed afloat until the following morning, when it finally sank, killing over 1,500 people.
- Katharine Hepburn and Barbra Streisand tied for Best Actress. (1969) It was the Oscar tie in over 30 years, and was even more dramatic because it was the first time the Academy Awards were broadcast internationally. Hepburn won for The Lion in Winter, while Streisand won for Funny Girl.
- The first abolition society was formed in the US. (1775) The Society for the Relief of Free Negroes Unlawfully Held in Bondage was founded by a Quaker teacher, Anthony Benezet, who also started one of the first schools for African-American children in the US. Among the supporters of the society were Benjamin Franklin, who later served as its president.
- The Donner Party set out on its journey. (1846) The party consisted of three families and their servants trying to get from Illinois to California. They became trapped in the Sierra Nevada mountains in the winter of 1846 and ended up having to resort to cannibalism to survive.
- The Black Sunday dust storm occurred. (1935) The storm was one of the worst of the Dust Bowl with over 300,000 tons of topsoil thrown in the air.
- The Grapes of Wrath was published. (1939) Steinbeck wrote the now-classic novel about the Great Depression in order to "put a tag of shame" on those who caused the Great Depression. It went on to win both the Pulitzer prize and the Nobel prize for literature.
- The heaviest hailstones ever recorded fell in Bangladesh. (1986) Hailstones weighing over 2 pounds (over 1 kg) each fell in Gopalganj, Bangladesh, killing over 90 people.