Editing 1787 (section)

=== July&ndash;September ===
* [[July 13]] &ndash; 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]].<ref name="Harper1787"/>
* [[July 18]] &ndash; The United States ratifies its first treaty with the Sultanate of Morocco.<ref name="Harper1787"/>
* [[August 9]] &ndash; South Carolina [[State cessions|cedes]] to the United States its claims to a 12-mile wide strip of land that runs across northern Alabama and Mississippi.<ref name="Harper1787"/>
* [[August 10]] &ndash; [[Wolfgang Amadeus Mozart]] composes his famous [[Eine kleine Nachtmusik]].
* [[August 27]] &ndash; Launching a {{Convert|45|ft|m|adj=on}} steam powered craft on the Delaware River, [[John Fitch (inventor)|John Fitch]] demonstrates the first U.S. [[patent]] for his design.
* [[September 13]] &ndash; [[Prussian invasion of Holland|Prussian troops invade]] the [[Dutch Republic]]; two days later the [[Johann Friedrich von Salm-Grumbach|Rhinegrave Salm]] gave up Utrecht. Within a few weeks 40,000 [[Patriots (Dutch Republic)|Patriots]] (out of a population of 2,000,000) go into exile in [[French Flanders|Northern France]].
* [[September 17]] &ndash; The [[United States Constitution]] is signed by the [[Constitutional Convention (United States)|Constitutional Convention]] in [[Philadelphia]].<ref name="Harper1787"/>
* [[September 24]] &ndash; Washington Academy (later [[Washington & Jefferson College]]) is chartered by the [[Pennsylvania General Assembly]].<ref>{{cite book|last=Coleman|first=Helen Turnbull Waite|title=Banners in the Wilderness: The Early Years of Washington and Jefferson College|publisher=University of Pittsburgh Press|year=1956|url=https://archive.org/details/bannersinthewild012852mbp|oclc=2191890|page=[https://archive.org/details/bannersinthewild012852mbp/page/n252 199]}}</ref>