Events January–March January 20 – At Versailles, Great Britain signs preliminary peace treaties with the Kingdom of France and the Kingdom of Spain. January 23 – The Confederation Congress ratifies two October 8, 1782, treaties signed by the United States with the United Netherlands. February 3 – American Revolutionary War: Great Britain acknowledges the independence of the United States of America. At this time, the Spanish government does not grant diplomatic recognition. February 4 – American Revolutionary War: Great Britain formally declares that it will cease hostilities with the United States. February 5 – 1783 Calabrian earthquakes: The first of a sequence of five earthquakes strikes Calabria, Italy (February 5–7, March 1 & 28), leaving 50,000 dead. February 7 – The Great Siege of Gibraltar is abandoned. February 26 – The United States Continental Army's Corps of Engineers is disbanded. March 5 – The last celebration of Massacre Day is held in Boston, Massachusetts. March 15 – Newburgh Conspiracy: A potential uprising in the Continental Army stationed at Newburgh, New York is defused, when George Washington asks the officers to support the supremacy of the United States Congress. April–June April – General George Washington sends a letter to the 13 governors of the Confederation of the United States, regarding the needs of the nation. April 3 – A Peace and Commercial Treaty is signed between the newly-formed United States and Sweden in Paris, among the first acts of state concluded between the U.S. and a foreign power. April 8 – The Crimean Khanate, which has existed since 1441 and is a late remnant of the Mongol Golden Horde, is annexed by the Russian Empire of Catherine the Great. April 9–28 – Second Anglo-Mysore War: Siege of Bednore – Tipu Sultan of Mysore with 100,000 troops besieges 1600 British East India Company troops who are obliged to surrender with honours of war. April 15 – Preliminary articles of peace ending the American Revolutionary War are ratified by the Congress of the Confederation in the United States. April 18 – Three-Fifths Compromise: The first instance of black slaves in the United States of America being counted as three fifths of persons (for the purpose of taxation), is included in a resolution of the Congress of the Confederation (this is later adopted in the 1787 Constitution). May 13 – The Society of the Cincinnati, a fraternal organization for American veterans of the American