On March 18, 1899, Phoebe, a satellite of Saturn, became the first moon to be discovered with photographs, taken in August 1898, by William Henry Pickering.
Also on the Eighteenth of March:
- The Sunflower Student Movement (2014)
- President Eisenhower signed a bill bringing Hawaii into the United States (1959)
- South Africans voted to get rid of the color bar (1992)