Construction began on the Hoover Dam in Nevada.
It was originally called the Boulder Dam.
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Dutch artist Wilfred Stijger broke the world record for the tallest sandcastle.
Spanish conquistadors defeated a large Aztec army at the Battle of Otumba.
Sir Isaac Newton gained a master's degree from Trinity College, Cambridge, England.
The world celebrated the introduction of sliced bread for the first time.
'Harry Potter and the Deathly Hallows – Part 2' premiered in London.