1800

As of March 1, when the Julian calendar acknowledged a leap day and the Gregorian calendar did not, the Julian calendar fell one day farther behind, bringing the difference to 12 days until February 28, 1900.

Events

January–March

January 1
* Quasi-War: Action of 1 January 1800 - A naval battle off the coast of Haiti, between four United States merchant vessels escorted by naval schooner, and a squadron of armed barges manned by Haitian pirates, under the command of general André Rigaud, ends indecisively.
* The Dutch East India Company dissolves.
February 7 - A public plebiscite in France confirms Napoleon as First Consul, by a substantial majority.
February 11 - Infrared radiation is discovered by astronomer Sir William Herschel.
February 22 - The Baker rifle, designed by Ezekiel Baker, is selected by the British Board of Ordnance as a new standard.
March 14 - Papal conclave, 1799–1800: cardinal Barnaba Chiaramonti succeeds Pius VI as Pius VII, the 251st pope. He is crowned on March 21, in Venice.
March 17 - The British Royal Navy ship of the line,, catches fire off the coast of Capraia, with the loss of 673 lives.
March 20 - Alessandro Volta describes his new invention, the voltaic pile, the first chemical battery, in a letter to the Royal Society of London.
March 26 - British Royal Navy officer Henry Waterhouse first charts the Antipodes Islands.

April–June

April 2
* Ludwig van Beethoven's Symphony No. 1 premieres at the Burgtheater, in Vienna.
* The Treaty of Constantinople establishes the Septinsular Republic, the first autonomous Greek state since the Fall of the Byzantine Empire.
April 3 - The first voting, albeit indirect, begins in the 1800 United States presidential election as voters in the state of New York make [1800 United States presidential election in New York|their selections for the New York (state)|New York state legislature], which in turn will vote on October 31 for the state's 12 presidential electors. A majority of state legislature members are from the Democratic-Republican Party, rather than the Federalist Party. At the time, only 4 of the 16 U.S. states have a popular vote for the presidential electors and the President. The other 12, including New York, have a popular vote for the state legislature, but not for the president. At the time, neither of the major parties have picked their nominees for president and vice president. The result will not be certified until February, 1801.
April 6 - War of the Second Coalition: Siege of Genoa - General André Masséna is surrounded by 40,000 Austrian troops under Field Marshal Michael von Melas and blockaded by a strong British squadron under Lord Keith.
April 24 - The U.S. Library of Congress is founded in Washington, D.C.
May 14 - Second Coalition: French forces under General Louis-Alexandre Berthier are halted by 400 Austro-Piedmont soldiers, at Fort Bard in the Aosta Valley.
May 15 - Napoleon and his French army —not including the field artillery and baggage trains— begin crossing the Alps. He selects the shortest route through the Great St Bernard Pass, and invades after five days traversing the northern region of Italy.
June 2 - The first smallpox vaccination is made in North America, at Trinity, Newfoundland.
June 3 - U.S. President John Adams moves to Washington. Because the President's Mansion is still under construction, President Adams takes up residence at Tunnicliffe's City Hotel near the unfinished U.S. Capitol Building.
June 4 - War of the Second Coalition: Siege of Genoa - The French army is evacuated from Genoa. Marshal André Masséna is allowed to march out, with all the honours of war. A portion of his force joins General Louis-Gabriel Suchet, and the rest is conveyed in British ships to Antibes.
June 14
* War of the Second Coalition: Battle of Marengo - Napoleon defeats the Austrian troops near Marengo, Italy.
* French general Jean-Baptiste Kléber is assassinated in Cairo by Syrian Kurdish Muslim student Suleiman al-Halabi.
June 15 - Convention of Alessandria : Austria agrees to evacuate much of Italy.
June 19 - War of the Second Coalition: Battle of Höchstädt - General Jean Victor Marie Moreau leads French forces to victory, opening the Danube passageway to Vienna.
June 27 - War of the Second Coalition: Battle of Neuburg - General Claude Lecourbe leads French forces to victory, securing control of the Danube from Austria.

July–September

July 2 - The Union with Ireland Act 1800 is passed by the Parliament of Great Britain; the Irish Parliament passes similar legislation in the following month, uniting the two kingdoms and abolishing the Parliament of Ireland.
July 10 - Fort William College is established by Lord Wellesley, British Governor-General of India, in Calcutta, to promote Bengali, Hindi and other vernaculars of the Indian subcontinent.
August 1 - King George III gives royal assent to the second Act of Union to unite the Kingdom of Great Britain and Kingdom of Ireland into the United Kingdom of Great Britain and Ireland, effective on January 1, 1801.
August 30 - The plot by African-American blacksmith and slave Gabriel Prosser to seize Richmond, Virginia, and guide a slave uprising, is thwarted by a massive downpour on the evening that it is set to begin; two other slaves have revealed Prosser's plans to authorities, who have prepared to follow him to the rendezvous point and arrest the conspirators, so that "neither the geographical extent of the plot nor the number of insurgents in the conspiracy was revealed"; eventually, 25 slaves, including Prosser, will be captured, tried and hanged.
September 4 - Siege of Malta (1798–1800): The French garrison in Valletta surrenders to British troops, who had been called at the invitation of the Maltese. The islands of Malta and Gozo become the Malta Protectorate.
September 30 - The Convention of 1800, or Treaty of Mortefontaine, is signed between France and the United States of America, ending the Quasi-War.

October–December

October 1 - Third Treaty of San Ildefonso: Spain returns Louisiana (New Spain) to France, in return for the Tuscany area of Italy.
October 7 - French privateer Robert Surcouf leads the 150-man crew of his corvette to capture the 40-gun, 437-man British East Indiaman in the Indian Ocean.
November 1
* U.S. President John Adams becomes the first President of the United States to live in the Executive Mansion.
* Middlebury College is granted its charter by the Vermont General Assembly.
November 17 - The United States Congress holds its first Washington, D.C., session.
November 22 - War of the Second Coalition: Hostilities resume.
December 3
* War of the Second Coalition: Battle of Hohenlinden - The French army defeats Habsburg and Bavarian troops.
* The 1800 United States presidential election: The Electoral College casts votes for president and Vice President that results in a tie between Thomas Jefferson and Aaron Burr, requiring a contingent election which will select Jefferson as president.
December 24
* The Plot of the rue Saint-Nicaise fails to kill Napoleon Bonaparte.
* Pierre Coudrin and Henriette Aymer de la Chevalerie found the Congregation of the Sacred Hearts of Jesus and Mary in Paris.
December 25 – The Armistice of Steyr is signed between French and Imperial forces in Germany, ending active hostilities of the War of the Second Coalition in Germany.

Births

January–June

January 1 - Francis Egerton, 1st Earl of Ellesmere, English landowner
January 4 - Martha Christina Tiahahu, Moluccan freedom fighter, national heroine of Indonesia
January 6 - Anna Maria Hall, Irish writer
January 7 - Millard Fillmore, 13th President of the United States
January 11 - Ányos Jedlik, Hungarian physicist, inventor of the dynamo
January 12 - George Villiers, 4th Earl of Clarendon, English diplomat, statesman
January 14 - Ludwig von Köchel, Austrian musicologist
January 17 - Caleb Cushing, American statesman, diplomat
January 24 - Edwin Chadwick, English social reformer
Johann Gerhard Oncken, German Baptist preacher
Elizabeth Ann Whitney, American Mormon leader
January 27 - Evelyn Denison, 1st Viscount Ossington, English statesman
February 1 - Brian Houghton Hodgson, English civil servant
February 6 - Achille Devéria, French painter, lithographer
February 9
Hyrum Smith, American religious leader
Joseph von Führich, Austrian painter
March 2 - Yevgeny Baratynsky, Russian poet
March 3 - Heinrich Georg Bronn, German geologist, paleontologist
March 4 - William Price, Welsh physician, eccentric
March 10
*Victor Aimé Huber, German social reformer
*George Hudson, English railway financier
March 13 - Mustafa Reşid Pasha, Turkish statesman, diplomat
March 16 - Emperor Ninkō of Japan
March 17 - Rudolf Ewald Stier, German Protestant churchman, mystic
March 20
*Braulio Carrillo Colina, Costa Rican head of state, politician
*Gottfried Bernhardy, German philologist, literary historian
March 25 - Ernst Heinrich Karl von Dechen, German geologist, mineralogist
March 28 - Johann Georg Wagler, German herpetologist
April 2 - Andrzej Artur Zamoyski, Polish nobleman
April 4 - Tokugawa Nariaki, Japanese daimyō of Mito
April 10 - Henri-Gustave Delvigne, French soldier, weapon inventor
April 15 - James Clark Ross, British naval officer, explorer
April 16
*Jakob Heine, German orthopaedist
*George Bingham, 3rd Earl of Lucan, British soldier
May 1 - James Black, American bladesmith, creator of the original Bowie knife
May 4 - John McLeod Campbell, Scottish churchman
May 5 - Louis Christophe François Hachette, French publisher
May 6 - Roman Sanguszko, Polish noble
May 9 - John Brown, American abolitionist
May 30 - Karl Wilhelm Feuerbach, German geometer
June 1 - Charles Fremantle, British Royal Navy officer
June 2 - Nicholas P. Trist, secretary to President Andrew Jackson of the U.S.
June 3 - Gustaw Potworowski, Polish activist
June 12 - Samuel Wright Mardis, American politician
June 17 - William Parsons, 3rd Earl of Rosse, Irish astronomer
June 23 - Karol Marcinkowski, Polish physician, social activist
June 30 - Richard Bethell, 1st Baron Westbury, Lord Chancellor of Great Britain

July–December

July 15 - Sidney Breese, American senator from Illinois, father of the Illinois Central Railroad
July 19 - Juan José Flores, 2-time President of Ecuador
July 21 - Constance Trotti, Belgian salonniére, culture patron
July 24 - Henry Shaw, American botanist
July 29 - George Bradshaw, English timetable publisher
July 31 - Friedrich Wöhler, German chemist
August 12 - Jean-Jacques Ampère, French philologist, writer and historian
August 20 - Bernhard Heine, German physician, bone specialist and inventor
August 22
*Edward Bouverie Pusey, English churchman
*Frank Stone, English painter
September 1 - Giuseppe Gabriel Balsamo-Crivelli, Italian naturalist
September 22 - George Bentham, English botanist
October 14 - John Hogan, Irish sculptor
October 19 - Salome Sellers, American centenarian, last surviving person from the 18th century
October 23 - Henri Milne-Edwards, French zoologist
October 26 - Helmuth von Moltke the Elder, German field marshal
November 21 - Barney Aaron, English bare-knuckle boxer
December 3 - France Prešeren, Slovenian romantic poet
December 25 - John Phillips, English geologist
December 29 - Charles Goodyear, American inventor of the vulcanization process

Deaths

1800

Events

January&ndash;March

April&ndash;June

July&ndash;September

October&ndash;December

Births

January&ndash;June

July&ndash;December

Deaths

January&ndash;June

July&ndash;December

Date unknown

January–March

April–June

July–September

October–December

January–June

July–December

January–June

July–December