King Carlos I of Portugal and his heir were assassinated in Lisbon.
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MP's in the UK voted in favor of triggering the European Union Bill (Article 50), which gave the government the power to prepare to leave the European Union.
Isaac Briggs & William Longstreet was awarded a patent for the first steamboat in the US.
An atomic bomb explosion was aired on TV for the first time.
The first reusable spacecraft called ''Space Shuttle Columbia" broke apart when returning to Earth, and all seven astronauts on board died.
The Civil Marriage Act was introduced, making same-sex marriage legal in Canada.
