The first four-engine aircraft was built and flown by Igor Sikorsky.
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The first US airmail stamps were issued, costing 24 cents.
Three astronauts, Richard J. Hieb, Thomas D. Akers, and Pierre J. Thuot, simultaneously walked in space for the first time.
The Beatles movie, 'Let it Be,' premiered.
Winston Churchill made his famous speech to the House of Commons.
A new study was published in the journal 'Nature Geoscience,' which showed that the moon is still shrinking with recent moonquakes as it cools.
