Editing 1801 (section)

=== January–March ===

[[File:Flag of the United Kingdom.svg|thumb|January 1: The [[United Kingdom of Great Britain and Ireland]] is formed.]]
*[[January 1]]
** The legislative union of Great Britain and Ireland is completed under the [[Act of Union 1800]], bringing about the [[United Kingdom of Great Britain and Ireland]], and the abolition of the [[Parliament of Ireland]].
** [[Giuseppe Piazzi]] discovers the asteroid and [[dwarf planet]] [[Ceres (dwarf planet)|Ceres]].
*[[January 3]] – [[Toussaint Louverture]] triumphantly enters [[Santo Domingo]], the capital of the former Spanish [[Captaincy General of Santo Domingo|colony of Santo Domingo]], which has become a colony of [[First French Empire|Napoleonic France]].
*[[January 31]] – [[John Marshall]] is appointed [[Chief Justice of the United States]].
*[[February 4]] – [[William Pitt the Younger]] resigns as [[Prime Minister of the United Kingdom]].
*[[February 9]] – The [[Treaty of Lunéville]] ends the [[War of the Second Coalition]] between France and Austria.  Under the terms of the treaty, all German territories left of the Rhine are officially annexed by France while Austria also has to recognize the Batavian, Helvetian, Cisalpine and Ligurian Republics.
*[[February 17]] – An [[Electoral College (United States)|electoral]] tie between [[Thomas Jefferson]] and [[Aaron Burr]] is resolved, when Jefferson is elected President of the United States and Burr Vice President by the [[United States House of Representatives]].
*[[February 27]] – Washington, D.C. is placed under the jurisdiction of the [[United States Congress]].
*[[March 10]] – The [[Census Act 1800|first census]] is held in Great Britain. The population of [[England and Wales]] is determined to be 8.9&nbsp;million,<ref>{{cite web|url=http://www.chronology.ndo.co.uk/1800-1849.htm|title=Chronology of State Medicine|access-date=August 10, 2007|archive-url=https://web.archive.org/web/20070809081353/http://www.chronology.ndo.co.uk/1800-1849.htm |archive-date=August 9, 2007}}</ref> with London revealed to have 860,035 residents. 1.5&nbsp;million people live in cities of 20,000 or more in England and Wales, accounting for 17% of the total English population.
*[[March 14]] – [[Henry Addington]] becomes [[First Lord of the Treasury]] and [[Chancellor of the Exchequer]], effectively [[Prime Minister of the United Kingdom]].
*[[March 21]] – [[Battle of Alexandria (1801)|Battle of Alexandria]] in Egypt: British troops defeat the French, but the British commander, Sir [[Ralph Abercromby]], dies later of a wound received in the action.
*[[March 23]] – Tsar [[Paul I of Russia]] is murdered; he is succeeded by his son [[Alexander I of Russia|Alexander I]].