October 20, 1632 - English architect Christopher Wren is born. He was responsible for rebuilding St. Paul's Cathedral after the Great Fire of London.
October 20, 1714 - George I is crowned King of England.
October 20, 1803 - The US government ratified the Louisiana Purchase, doubling the size of the country.
October 20, 1910 - The hull of the RMS Olympic (sister ship to the Titanic) was launched at the shipyard in Belfast, Ireland.