Harrison's Naval Longitude Clock
1765 British Longitude Act awards clockmaker John Harrison £10,000 for the invention of a naval longitude clock [1]
1869 The Golden Spike is driven, completing the first US Transcontinental Railroad at Promontory Summit, Utah, connecting the Central Pacific Railroad with the Union Pacific
1st White House Telephone
1877 US President Rutherford B. Hayes has the first White House telephone installed in the telegraph room
- 1908 1st Mother's Day observed (Philadelphia)
- 1910 Halley's Comet makes its closest approach to Earth in 1910 pass
- 1930 First US planetarium opens, the Adler Planetarium in Chicago
- 1960 US atomic submarine USS Triton completes first submerged circumnavigation of the globe
- 1990 French TGV-train hits record speed of 510.6 kph (317.3 mph)
- 2014 Kara Walker's artwork "The Subtlety" opens - an installation of a sphinx made of sugar at the Domino Sugar factory in Brooklyn, NY [1]
- 2021 Chinese safari park in Fuyang forced to apologize for not informing the public that three leopards had escaped April 19 and been roaming nearby neighborhoods
