1529 – The Siege of Vienna ends as the Austrians rout the invading Turks, turning the tide against almost a century of unchecked conquest throughout eastern and central Europe by the Ottoman Empire.
1793 – Queen Marie Antoinette of France is tried and convicted in a swift, pre-determined trial in the Palais de Justice, Paris, and condemned to death the following day.
1939 – The New York Municipal Airport (later renamed LaGuardia Airport) is dedicated.
1940 – The President of Catalonia, Lluís Companys, is executed by the Spanish dictatorship of Francisco Franco, making him the only European president to have been executed.
1954 – Hurricane Hazel devastates the eastern seaboard of North America, killing 95 and causing massive floods as far north as Toronto. As a Category 4 upon landfall, it is the strongest storm on record to strike as far south as North Carolina.
1956 – Fortran, the first modern computer language, is shared with the coding community for the first time.
1969 – Vietnam War; The Moratorium to End the War in Vietnam is held in Washington D.C. and across the US. Over two million demonstrate nationally; about 250,000 in Washington D.C..
1970 – Thirty-five construction workers are killed when a section of the new West Gate Bridge in Melbourne collapses.