Events of 1787

January–June

• January 6 – The North Carolina General Assembly authorizes nine commissioners to purchase of land for the county seat of Chatham County. The town is named Pittsborough (later shortened to Pittsboro) for William Pitt the Younger.

• January 11 – William Herschel discovers Titania and Oberon, 2 moons of Uranus.

• February 4 – Shays' Rebellion fails.

• February 28 – A charter is granted establishing the institution known today as the University of Pittsburgh.

• April 2 – A Charter of Justice is signed providing the authority for the establishment of the first New South Wales (ie Australian) Courts of Criminal and Civil Jurisdiction.

• May 13 – Captain Arthur Phillip leaves Portsmouth, England with 11 ships packed with 1,000 convicts and their jailers to establish a penal colony in Australia.

• May 14 – In Philadelphia, Pennsylvania, delegates begin arriving to write a new Constitution for the United States.

• May 25 – In Philadelphia, Pennsylvania, delegates begin to convene a Constitutional Convention intended to amend the Articles of Confederation. However, a new Constitution for the United States is eventually produced. George Washington presides over the Convention.

• May – Orangist troops attack Vreeswijk, Harmelen and Maarssen; civil war starts in the Netherlands.

• June 6 – Franklin College, named for Benjamin Franklin, opens in Lancaster, Pennsylvania. It later merges with Marshall College to become Franklin and Marshall College.

• 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 Frederick, the king of Prussia, is captured by patriots and taken to Goejanverwellesluis, and not allowed to travel to the Hague.

July–December

• July 13 – The U.S. Congress enacts the Northwest Ordinance establishing governing rules for the Northwest Territory. It also establishes procedures for the admission of new states and limits the expansion of slavery.

• July 15 – Lord's cricket ground is established and the MCC incorporated.

• 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 enter the Netherlands. 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 adopted by the Constitutional Convention in Philadelphia.

• October 1 – Russo-Turkish War, 1787-1792 – 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 a New York paper.

• October 29 – Wolfgang Amadeus Mozart's opera Don Giovanni (libretto by Lorenzo da Ponte) premieres in the Estates Theatre in Prague.

• December 7 – Delaware ratifies the Constitution and becomes the first U.S. state.

• December 8 – Mission La Purisima Concepcion is founded by Father Fermín Francisco de Lasuén, becoming the 11 mission in the California mission chain.

• December 12 – Pennsylvania becomes the second U.S. state.

• December 18 – New Jersey becomes the third U.S. state.

Undated

• In Britain, Thomas Clarkson and Granville Sharp found the Society for the Abolition of the Slave Trade with support from John Wesley, Josiah Wedgwood and others.

• The North Carolina General Assembly incorporates Waynesborough and designates it the county seat for Wayne County, North Carolina.

• The element Silicon is first identified by Antoine Lavoisier as a component of the Latin term silex or "Flints" (meaning "Hard Rocks").

Births

• January 1 – Manuel José Arce, Revolutionary General and first President of The Federal Republic of Central America. (d. 1847)

• February 10 – William Bradley, Britain's tallest man ever (d. 1820)

• March 7 – George Bethune English, American explorer and writer (d. 1828)

• March 11 – Ivan Nabokov, Russian General

• March 17 – Edmund Kean, British actor (d. 1833)

• April 26 – Ludwig Uhland, German poet (d. 1862)

• November 18 – Louis Daguerre, French artist and chemist (d. 1851)

• November 21 – Samuel Cunard, Canadian business, prominent Nova Scotian, founder of the Cunard Line (d. 1865)

• December 10 – Thomas Hopkins Gallaudet, American educator (d. 1851)

• December 16 – Mary Russell Mitford, English novelist and dramatist (d. 1855)

Deaths

• February 13

• *Rudjer Boscovich, Croatian scientist and diplomat (b. 1711)

• *Charles Gravier, comte de Vergennes, French statesman and diplomat (b. 1717)

• April 1 – Floyer Sydenham, English classical scholar (b. 1710)

• April 2 – Thomas Gage, British general (b. 1719)

• May 10 – William Watson, English physician and scientist (b. 1715)

• May 28 – Leopold Mozart, Austrian composer (b. 1719)

• June 20 – Carl Friedrich Abel, German composer (b. 1723)

• July 4 – Charles de Rohan, prince de Soubise, Marshal of France (b. 1715)

• August 1 – Alphonsus Liguori, Italian founder of the Redemptionist order (b. 1696)

• October 7 – Henry Muhlenberg, German-born founder of the U.S. Lutheran Church (b. 1711)

• November 3 – Robert Lowth, English bishop and grammarian (b. 1710)

• November 15 – Christoph Willibald Gluck, German composer (b. 1714)

• December 18 – Francis William Drake, British admiral and Governor of Newfoundland (b. 1724)

• December 18 – Soame Jenyns, English writer (b. 1704)