1712, Jean-Jacques Rousseau was born in Geneva.
In 1751, James Madison, the "father" of the American Constitution, was born at Belle Grove Plantation, Virginia.
In 1894, the United States made Labor Day (the first Monday in September) an official holiday.
In 1914, Gavrilo Princip, a Bosnian Serb and a Yugoslav nationalist, assassinated Archduke Franz Ferdinand of Austria and his wife while the two were travelling over the Latin Bridge in Sarajevo, Bosnia. Franz Ferdinand was the heir to the Austro-Hungarian throne. His assassination by the Bosnian Serb triggered a set of cascading events which eventually produced the First World War, and thus also the history which could not have happened as it did but for that war.
In 1919, Germany and the Allied powers signed the ill-fated peace Treaty of Versailles.
In 1922, the Irish Civil War began.
In 1967, the State of Israel annexed East Jerusalem.
In 1969, spontaneous demonstrations erupted when the New York Police Department raided the Stonewall Inn, a gay bar in Greenwich Village, New York City. The Stonewall Riots, as we remember the demonstrations today, became a definitive event in the Gay Rights Movement in the United States.
In 1978, the Supreme Court of the United States handed down its decision in Regents of the University of California v. Bakke.
In 2004, the Coalition Provisional Authority in Iraq, led by L. Paul Bremer, transferred power to the Iraqi Interim Government, led by Iyad Allawi, thus nominally ending America's post-invasion governance of Iraq.