January 3 – The third Treaty of Hopewell is signed, between the United States and the Choctaw. January 6 – The outward bound East Indiaman Halsewell is wrecked on the south coast of England in a storm, with only 74 of more than 240 on board surviving. February 2 – In a speech before The Asiatic Society in Calcutta, Sir William Jones notes the formal resemblances between Latin, Greek, and Sanskrit, laying the foundation for comparative linguistics and Indo-European studies. March 1 – The Ohio Company of Associates is organized by five businessmen at a meeting at the Bunch-of-Grapes Tavern in Boston, to purchase land from the United States government to form settlements in what is now the U.S. state of Ohio. March 13 – Construction begins in Dublin on the Four Courts Building, with the first stone laid down by the United Kingdom's Viceroy for Ireland, the Duke of Rutland. April 2 – The Creek Nation declares war on the U.S. State of Georgia over the matter of white settlers on land not ceded by the Nation. A truce is negotiated on April 17 between Creek Chief Alexander McGillivray (Hoboi-Hili-Miko) and U.S. Army General Lachlan McIntosh but is soon repudiated. April 11 – Columbia College (modern-day Columbia University) holds its first graduation, with eight students, including DeWitt Clinton. April 25 – The United States and the Kingdom of Portugal sign their first commercial treaty, but it is never ratified. April 27 – British astronomer William Herschel publishes his first list of his discoveries, Catalogue of One Thousand New Nebulae and Clusters of Stars; two additional books are published in 1789 and 1802. May 1 – Mozart's opera The Marriage of Figaro premieres in Vienna. May 21 – The trial in the Affair of the Diamond Necklace ends in Paris. June 2 – The Tignon law is enacted by Spanish Governor of Louisiana Esteban Rodríguez Miró, to force black women to wear a tignon headscarf. June 6 – Nathaniel Gorham is chosen as the new President of the U.S. Confederation Congress to substitute for John Hancock, who cannot take office because of illness.