Editing 1848 (section)

=== April–June ===
* [[April 3]] – The [[Chicago Board of Trade]] is founded by 82 [[Chicago]] merchants and business leaders.
* [[April 10]]
** A [[Chartism|Chartist]] 'Monster Rally' is held in [[Kennington Park]] London, headed by [[Feargus O'Connor]]. A [[Chartism#1848 petition|petition demanding the franchise]] is presented to the [[Parliament of the United Kingdom]].
** The [[Illinois and Michigan Canal]] is completed.
* [[April 11]] – The first Hungarian national government is formed, under the leadership of [[Lajos Batthyány]]. The [[April Laws]], the first democratic revolutionary laws in [[Hungary]], are promulgated, putting an end to the [[Feudalism|feudal privileges of the nobility]] and [[serfdom]]; proclaiming the [[freedom of religion]], [[freedom of the press]] and foundation of the [[Hungarian National Bank]]; and organising the first democratic [[election]] in Hungary based in popular representation, a national guard and reunion of [[Transylvania]] with Hungary. The Habsburg emperor, and Hungarian king [[Ferdinand I of Austria]], ratify these laws, which form the basis of modern Hungary.
* [[April 18]] – The [[Second Anglo-Sikh War]] breaks out in the [[Punjab (region)|Punjab]].
* [[April 25]] – Captain [[Francis Crozier]] and Commander [[James Fitzjames]] of the [[Royal Navy]] deposit the final formal record ever recovered from the [[Franklin Expedition]] in a cairn on [[King William Island]], after deserting their ships, HMS ''Erebus'' and HMS ''Terror'', with their surviving 105 crew members on April 22 to attempt to march to the mainland of North America. 
* [[April 27]] – The second abolition of slavery in France and its colonies initiated by [[Victor Schœlcher]].
* [[April 29]] – [[Pope Pius IX]] publishes an allocution announcing his refusal to support Piedmont-Sardinia in its war with Austria, and dispelling hopes that he might serve as ruler of a pan-Italian republic. The allocution, by which Pius is seen to withdraw his moral support for the [[Italian unification]] movement, is a key first step in the soon-to-be crushing reaction against the revolutions of 1848.
* [[May 3]] – The boar-crested [[Anglo-Saxon]] [[Benty Grange helmet]] is discovered in a [[Tumulus|barrow]] on the [[Benty Grange]] farm in [[Derbyshire]].
* [[May 13]] – "[[Maamme]]", the [[national anthem]] of Finland written by German composer [[Fredrik Pacius]] and Finnish poet [[Johan Ludvig Runeberg]], was performed for the first time.
* [[May 15]]
** [[Radicalism (historical)|Radicals]] invade the French [[Chamber of Deputies (France)|Chamber of Deputies]].
** 40,000 [[Romanians]] meet at [[Câmpia Libertății]] in [[Blaj]], to protest [[Transylvania]] becoming a part of Hungary.<ref name=Stoica1>{{cite book|last=Stoica|first=Vasile|title=The Roumanian Question: The Roumanians and their Lands|year=1919|publisher=Pittsburgh Printing Company|location=Pittsburgh|page=23|url=http://www.wdl.org/en/item/7314/view/1/23/}}</ref>
* [[May 18]] – The '[[Frankfurt Parliament]]' (''Nationalversammlung''), the first German National Assembly, opens in [[Frankfurt]].
* [[May 19]] – The [[Treaty of Guadalupe Hidalgo]] of February 2, ending the [[Mexican–American War]], is ratified by the Mexican government.
* [[May 29]] – [[Wisconsin]] is admitted as the 30th [[U.S. state]].
* [[May 30]] – The [[Prudential plc|Prudential]] Mutual Assurance Investment and Loan Association is established at [[Hatton Garden]] in London (England) to provide loans to professional and working people, origin of the multinational life [[insurance]] and [[financial]] services group.<ref>{{cite web|url=http://www.prudential.co.uk/prudential-plc/aboutpru/ourhistory/timeline/1826_1901/1826/|title=Timeline 1826–1901|access-date=2010-08-30|publisher=Prudential plc|archive-url=https://web.archive.org/web/20100813232819/http://www.prudential.co.uk/prudential-plc/aboutpru/ourhistory/timeline/1826_1901/1826/|archive-date=2010-08-13|url-status=dead}}</ref>
* [[June]] – The [[Serbians]] from [[Vojvodina]] start a rebellion against the Hungarian government.
* [[June 2]]–[[June 12|12]] – The [[Prague Slavic Congress, 1848|Prague Slavic Congress]] brings together members of the [[Pan-Slavism]] movement.
* [[June 17]] – The Austrian army bombards [[Prague]], and crushes a working-class revolt.
* [[June 21]] – [[Wallachian Revolution of 1848]]: The [[Proclamation of Islaz]] is made public, and a [[Romanians|Romanian]] revolutionary government led by [[Ion Heliade Rădulescu]] and [[Christian Tell]] is created.
* [[June 22]] – The French government dissolves the [[National Workshops|national workshops]] in Paris, giving the workers the choice of joining the army or going to workshops in the provinces. The following day, the [[June Days Uprising]] begins in response.