May 25 – In Philadelphia, delegates begin to convene the Constitutional Convention, intended to amend the Articles of Confederation (however, a new United States Constitution is eventually produced). George Washington presides over the Convention. May – Orangist troops attack Vreeswijk, Harmelen and Maarssen; civil war starts in the Dutch Republic. May 31 – The original Lord's Cricket Ground in London holds its first cricket match; Marylebone Cricket Club founded. June 20 – Oliver Ellsworth moves at the Federal Convention that the government be called the United States. June 28 – Princess Wilhelmina of Orange, sister of King Frederick William II of Prussia, is captured by Dutch Republican patriots, taken to Goejanverwellesluis and not allowed to travel to The Hague. July–September July 13 – The Congress of the Confederation enacts the Northwest Ordinance, establishing governing rules for the Northwest Territory (the future states of Ohio, Indiana, Illinois, Michigan and Wisconsin). It also establishes procedures for the admission of new states, and limits the expansion of slavery. July 18 – The United States ratifies its first treaty with the Sultanate of Morocco. August 9 – South Carolina cedes to the United States its claims to a 12-mile wide strip of land that runs across northern Alabama and Mississippi. August 27 – Launching a steam powered craft on the Delaware River, John Fitch demonstrates the first U.S. patent for his design. September 13 – Prussian troops invade the Dutch Republic. Within a few weeks 40,000 Patriots (out of a population of 2,000,000) go into exile in France (and learn from observation the ideals of the French Revolution). September 17 – The United States Constitution is signed by the Constitutional Convention in Philadelphia. September 24 – Washington Academy (later Washington & Jefferson College) is chartered by the Pennsylvania General Assembly. October–December October 1 – Russo-Turkish War (1787–92) – Battle of Kinburn: Alexander Suvorov, though sustaining a wound, routs the Turks. October 27 – The first of The Federalist Papers, a series of essays calling for ratification of the U.S. Constitution, is published in The Independent Journal, a New York newspaper. October 29 – Wolfgang Amadeus Mozart's opera Don Giovanni (libretto by Lorenzo Da Ponte) premieres in the Estates Theatre in Prague. November 1 – The first secondary education school open to girls in Sweden, Societetsskolan, is founded in Gothenburg. November 21 – Treaty of Versailles (1787) signed, forming an alliance between the Kingdom of