April 3 - Jêdrzej Kitowicz, Polish priest (b. 1727/1728)
June 16 - Johann Adam Hiller, German composer (b. 1728)
September 29 - Michael Hillegas, first Treasurer of the United States (b. 1728)
November 19 - Pietro Guglielmi, Italian composer (b. 1728)
November 23 - Richard Graves, British writer (b. 1715)
Events
January 1 - French rule ends in Haiti. Haiti becomes the first black republic and first independent country in the West Indies.
February 14 - Karadjordje leads the First Serbian Uprising against the Ottoman Empire.
February 16 - First Barbary War: Stephen Decatur leads a raid to burn the pirate-held frigate USS Philadelphia.
February 21 - The first self-propelling steam locomotive makes its outing at the Pen-y-Darren ironworks in Wales.
February 24 - London's Drury Lane Theatre burns to the ground, leaving owner Richard Brinsley Sheridan destitute.
March 4 - The Battle of Vinegar Hill, colony of New South Wales (Australia), when Irish convicts (some of whom had been involved in Ireland’s Battle of Vinegar Hill in 1798) led the colony’s only significant convict uprising.
March 10 - Louisiana Purchase: In St. Louis, a formal ceremony is conducted to transfer ownership of the Louisiana Territory from France to the United States.
March 21 - Code Napoléon is adopted as French civil law.
April 2 - Forty merchantmen are wrecked when a convoy led by HMS Apollo runs aground off Portugal.
April 5 - High Possil Meteorite: The first recorded meteorite in Scotland falls in Possil.
May 14 - The Lewis and Clark Expedition departs from Camp Dubois and begins its historic journey by traveling up the Missouri River.
June 15 - New Hampshire approves the Twelfth Amendment to the United States Constitution, ratifying the document.
July 11 - Vice President of the United States Aaron Burr mortally wounds former Secretary of the Treasury Alexander Hamilton in a duel.
July 12 - Former United States Secretary of the Treasury Alexander Hamilton dies after being shot in a duel.
August 20 - Lewis and Clark Expedition: the "Corps of Discovery", exploring the Louisiana Purchase, suffers its only death when sergeant Charles Floyd dies, apparently from acute appendicitis.
September 1 - Juno, one of the largest main belt asteroids, was discovered by German astronomer Karl Ludwig Harding.
September 25 - The Teton Sioux (a subdivision of the Lakota) demand one of the boats from the Lewis and Clark Expedition as a toll for moving further upriver.
October 9 - Hobart, capital of Tasmania, is founded.
November 30 - The Democratic-Republican-controlled United States Senate begins an impeachment trial against Federalist-partisan Supreme Court of the United States Justice Samuel Chase.
