Karl Marx was a German philosopher, economist, and political theorist who authored 'The Communist Manifesto' and 'Das Kapital.' His ideas laid the intellectual foundation for modern communism and profoundly influenced world history.
The Mexican army defeats French forces at the Battle of Puebla, a surprising victory that becomes a symbol of Mexican resistance and is celebrated as Cinco de Mayo.
Alan Shepard becomes the first American in space aboard the Freedom 7 spacecraft, completing a 15-minute suborbital flight just weeks after Yuri Gagarin's orbital mission.