Editing 1840 (section)

=== January–March ===
* [[January 3]] – One of the predecessor papers of the ''[[Herald Sun]]'' of [[Melbourne]], Australia, ''The Port Phillip Herald'', is founded.
* [[January 10]] – [[Uniform Penny Post]] is introduced in the United Kingdom.
* [[January 13]] – The steamship [[Lexington (steamship)|''Lexington'']] burns and sinks in icy waters, four miles off the coast of [[Long Island]]; 139 die, only four survive.
* [[January 19]] – Captain [[Charles Wilkes]]' [[United States Exploring Expedition]] sights what becomes known as [[Wilkes Land]] in the southeast quadrant of Antarctica, claiming it for the United States, and providing evidence that Antarctica is a complete continent.<ref>{{cite web|url=http://www.quarkexpeditions.com/antarctica/exploration.shtml|title=Antarctic Exploration — Chronology|access-date=2006-10-20|publisher=Quark Expeditions|year=2004|archive-url=https://web.archive.org/web/20060908120017/http://www.quarkexpeditions.com/antarctica/exploration.shtml |archive-date=2006-09-08}}</ref>
* [[January 21]] – [[Jules Dumont d'Urville]] discovers [[Adélie Land]] in Antarctica, claiming it for [[July Monarchy|France]].<ref>{{cite book|last=Guillon|first=Jacques|title=Dumont d'Urville|publisher=France-Empire|year=1986|location=Paris|isbn=2-7048-0472-9}}</ref>
* [[January 22]] – [[United Kingdom of Great Britain and Ireland|British]] colonists reach [[New Zealand]], officially founding the settlement of [[Wellington]].
* [[February]] – The [[Rhodes blood libel]] is made against the Jews of [[Rhodes]].
* [[February 5]] – [[Damascus Affair]]: The murder of a Capuchin friar and his Greek servant leads to a highly publicized case of [[blood libel]], against the Jews of [[Damascus]].
* [[February 6]] – The [[Treaty of Waitangi]], granting British sovereignty in New Zealand, is signed.
* [[February 10]] – [[Queen Victoria]] of the United Kingdom marries her cousin [[Albert, Prince Consort|Prince Albert of Saxe-Coburg and Gotha]].
* [[February 11]] – [[Gaetano Donizetti]]'s opera ''[[La fille du régiment]]'' premieres in Paris.
* [[March 1]] – [[Adolphe Thiers]] becomes prime minister of [[July Monarchy|France]].
* [[March 4]] – Alexander S. Wolcott and John Johnson open the world's first commercial photography portrait studio, their ''Daguerreian Parlor'', on [[Broadway (Manhattan)|Broadway]] in [[Manhattan]].
* [[March 9]] – The [[Wilmington and Raleigh Railroad]] is completed, from [[Wilmington, North Carolina]] to [[Weldon, North Carolina]]. At {{convert|161.5|mi|km}}, it is the world's longest railroad.<ref>{{cite web|url=http://www.historync.org/railroad-WWRR.htm|title=Railroad — Wilmington & Raleigh (later Weldon)|work=North Carolina Business History|year=2006|access-date=2011-12-02}}</ref>
* [[March 12]] – [[Paweł Strzelecki]] reaches [[Australia]]'s highest summit, [[Mount Kosciuszko]].