Letter collections started being collected from mailboxes in Boston, US.
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The Space Race began between the two Cold War rivals, the USA and the USSR.
The finalized copy of the United States Declaration of Independence was signed by congress.
Adolf Hitler became Führer of Germany following the death of President Paul von Hindenburg.
The Tower Subway in London became the first underground tube railway to open.
Researchers in South Korea developed a tattoo that monitors a person's health.
