Elon Musk bought a 9.2% stake in Twitter, amounting to $2.9 billion.
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NASA's Challenger Space Shuttle was launched from Florida on its maiden voyage.
Martin Luther King Jr. was assassinated.
Bill Gates and Paul Allen founded Microsoft.
Adolf Hitler formed the Schutzstaffel, the infamous paramilitary organization known to most as the SS.
Moscow was mentioned for the very first time in historical records when two princes met there for a great banquet.