Instagram was launched and gained 25,000 users on its first day.
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Euridice, the oldest-surviving opera, premiered in Florence, Italy.
The first American Chess Congress started in New York.
The American epic historical drama movie 'Spartacus' premiered in New York City.
The 51 Pegasi b planet was discovered. It was the first discovered exoplanet around a sun-like star.
Protestors took to the streets in Hong Kong after the government announced a ban on face masks.
