1791

January 1 – Austrian composer Joseph Haydn arrives in England, to perform a series of concerts. January 2 – Northwest Indian War: Big Bottom Massacre – The war begins in the Ohio Country, with this massacre. January 12 – Holy Roman troops reenter Liège, heralding the end of the Liège Revolution, and the restoration of its Prince-Bishops. January 25 – The British Parliament passes the Constitutional Act 1791, splitting the old province of Quebec into Upper and Lower Canada. February 8 – The Bank of the United States, based in Philadelphia, is incorporated by the federal government with a 20-year charter and started with $10,000,000 capital. February 21 – The United States opens diplomatic relations with Portugal. March 2 – French Revolution: The abolition of guilds is enacted. A mechanical semaphore line for rapid long-distance communication is demonstrated by Claude Chappe in Paris. March 4 – Vermont is admitted as the 14th U.S. state. March 13 – Thomas Paine's chief work Rights of Man (first part) is published in London. March – French Revolution: In France, the National Constituent Assembly accepts the recommendation of its Commission of Weights and Measures that the nation should adopt the metric system. April 21 – The first of forty boundary markers of the original District of Columbia, delineating the borders of the new District in the United States is laid at Jones Point Light in Alexandria, Virginia. April 29–May 8 – The first American ships reach Japan, brigantine Lady Washington captained by John Kendrick of Boston, and the brig Grace. May 3 – The Sejm of the Polish–Lithuanian Commonwealth proclaims the Constitution of May 3, 1791, the first modern codified constitution in Europe. June 20 – French Revolution: Flight to Varennes – The French Royal Family is captured when they try to flee in disguise. June 21 – The Ordnance Survey is founded in Great Britain for the production of maps. File:Malapeau_Claude-Nicolas_Translation_de_Voltaire_au_Panthéon.jpg|Translation of [[Voltaire]] File:PriestleyRiotsOldMeeting.