Construction began on the Hoover Dam in Nevada.
It was originally called the Boulder Dam.
Source
'Harry Potter and the Deathly Hallows – Part 2' premiered in London.
Sir Isaac Newton gained a master's degree from Trinity College, Cambridge, England.
Dutch artist Wilfred Stijger broke the world record for the tallest sandcastle.
The world celebrated the introduction of sliced bread for the first time.
NASA's Opportunity Mars rover launched from the Florida Cape Canaveral Space Force Station.
