- March 16 – Army Corps of Engineers re-established.
- March 16 – United States Military Academy of West Point is established.
- March 25–March 27 – Napoleonic Wars: The Treaty of Amiens between France and the United Kingdom ends the War of the Second Coalition.
- March 28 – H. W. Olbers discovers the asteroid Pallas.
- April 6 – Revenue Commission disbanded.
- April 10 – Great Trigonometric Survey of India begins with the measurement of a baseline near Madras.
- April 26 – A general amnesty signed by Napoleon Bonaparte allows all but about 1,000 of the most notorious émigrés of the French Revolution to return to France, as part of a reconciliary gesture to make peace with the various factions of the Ancien Regime that ultimately consolidates his own rule.
- May 19 – Napoleon Bonaparte establishes the French légion d'honneur (Legion of Honour).
- May 20 – By the Law of 20 May 1802, Napoleon Bonaparte reinstates slavery in the French colonies, revoking its abolition in the French Revolution.
- June 1 – Patent and Trademark Office within Department of State
- June 2 – Indigenous Australian Pemulwuy, a leader of the resistance to European settlement of Australia, is shot dead by Henry Hacking.
- June 8 – Haitian revolutionary Toussaint L'Ouverture is seized by French troops and sent to Fort de Joux for prison.
- July – Eleuthère Irénée du Pont founds E.I. du Pont de Nemours and Company, the modern DuPont Company.
- July 4 – At West Point, New York the United States Military Academy opens.
- July 5–August 28 – A general election in the United Kingdom brings victory for the Tories, led by Henry Addington.
- August 2 – In a plebiscite, Napoleon Bonaparte is confirmed as the First Consul.
- September 3 – William Wordsworth publishes the poem Westminster Bridge.
- September 11 – The Italian region of Piedmont becomes a part of the French First Republic.
- October 2 – War ends between Sweden and Tripoli. The United States also negotiates peace, but war continues over the size of compensation.
- October – The French army enters Switzerland.
[[[1802|edit]]] Date unknownEdit
- Treviranus uses the term biology for the first time.
- Thomas Wedgwood publishes an account of his experiments in photography, along with Humphry Davy. Since they had no means of fixing the image, their photographs quickly faded.
- William Symington builds the first successful steamship, the Charlotte Dundas.
- Ludwig van Beethoven performs his Moonlight Sonata for the first time.
- The English Parliament forbids pauper apprentices.
- The Nguyen Dynasty starts to rule in Vietnam.
- January 3 – Charles Pelham Villiers, British politician (d. 1898)
- February 11 – Lydia Maria Child, American abolitionist author (d. 1880)
- February 19 – Wilhelm Matthias Naeff, Swiss Federal Councillor (d. 1881)
- February 26 – Victor Hugo, French author (d. 1885)
- March 7 – Edwin Henry Landseer, British painter (d. 1873)
- April 4 – Dorothea Dix, American activist (d. 1887)
- May 2 – Heinrich Gustav Magnus, German chemist and physicist (d. 1870)
- June 23 – Pavel Nakhimov, Russian admiral (d. 1855)
- July 24 – Alexandre Dumas, père, French author (d. 1870)
- July 26 – Mariano Arista, President of Mexico (d. 1855)
- August 4 – Joseph Bonnell, Hero of the Texas Revolution (d. 1840)
- August 5 – Niels Henrik Abel, Norwegian mathematician (d. 1829)
- September 19 – Lajos Kossuth, Hungarian politician (d. 1894)
- October 31 – Benoît Fourneyron, French engineer (d. 1867)
- November 9 – Elijah P. Lovejoy, American abolitionist (d. 1837)
- November 19 – Solomon Foot, American politician (d. 1866)
- December 15 – Janos Bolyai, Hungarian mathematician (d. 1860)
- December 23 – Sara Coleridge, British scholar (d. 1852)
- February 2 – Welbore Ellis, 1st Baron Mendip, British statesman (b. 1713)
- February 3 – Pedro Rodríguez, Conde de Campomanes, Spanish statesman and writer (b. 1723)
- February 26 – Esek Hopkins, American Revolutionary War admiral (b. 1718)
- April 18 – Erasmus Darwin, English physician and botanist (b. 1731)
- May 22 – Martha Washington, first First Lady of the United States (b. 1731)
- July 22 – Marie François Xavier Bichat, French anatomist and physiologist (b. 1771)
- August 10 – Franz Aepinus, German philosopher (b. 1724)
- September 26 – Jurij Vega, Slovenian mathematician, physicist, and soldier (b. 1754)
- November 9 – Thomas Girtin, English artist (b. 1775)
- November 15 – George Romney, English artist (b. 1734)
- November 16 – André Michaux, French botanist (b. 1746)
- December 5 – Lemuel Francis Abbott, English portrait painter (b. 1716