March 19, 1932: Sydney Harbour Bridge opens. On 19 March 1932, the Sydney Harbour Bridge in Australia opened. Because of its huge arch, it is nicknamed "the Coathanger". Huge crowds walked across it that day, and today it is famous for its New Year's Eve fireworks.
1918 🔬 The US Congress set up official time zones across the country, so clocks in each region agree, just as the globe is divided into slices of time.
1933 🎨 Animator Richard Williams was born in Canada; he led the animation of Who Framed Roger Rabbit and wrote a famous guidebook for young animators.
1943 🔬 Mexican chemist Mario Molina was born; he discovered that some spray-can gases were harming the ozone layer, which led countries to ban them.