1848

1800–1850	USA [consumer products]	A revolution in retail and wholesale trade occurs: specialization transforms the urban retail market, replacing the general store with individual stores for hardware, groceries, dry goods, furnishing, books, tobacco, and so on. Cash-only sales policies are instituted around 1806.
1810–1859	USA [agriculture]	US cotton production, the vast majority of which is grown in the southern states, rises from 171,000 bales in 1810 to just under 5.4 million in 1859.
1840–1850	USA [farming]	Wheat becomes an increasingly important cash crop in the USA; production in 1839 is nearly 85 million bushels and climbs to over 100 million bushels in 10 years.
1840–1860	world [plagues and epidemics]	A cholera pandemic kills millions of people worldwide.
1841–1850	USA, UK [statistics and demography]	Emigration to the USA is 267,044 from Britain and 780,719 from Ireland.
1845–1958	Germany [earth sciences]	German naturalist and explorer Alexander von Humboldt lays the basis of modern geography with the publication of Kosmos/Cosmos, in which he arranges geographic knowledge in a systematic fashion.
1848–1849	Africa [exploration]	German explorers Johann Ludwig Krapf and Johannes Rebmann travel into the interior of Africa from its eastern coast, exploring the region of Kenya, and becoming the first Europeans to sight Mounts Kilimanjaro (Rebmann, May 1848) and Kenya (Krapf, December 1849).
1848	USA [food and drink]	John Curtis of Bangor, Maine, produces the first commerical chewing gum, ‘State of Maine Pure Spruce Gum’.
1848	France [art]	The French artist and caricaturist Honoré Daumier completes his series of lithographs Les Gens de justice/Lawyers.
1848	UK [aesthetics and criticism]	The English artists William Holman Hunt, John Everett Millais, and Dante Gabriel Rossetti found the Pre-Raphaelite Brotherhood. Rejecting the materialism and industrialization of Victorian England, they seek an art which has the moral and religious integrity of the medieval world.
1848	UK [companies and organizations]	English stationery company W H Smith and Sons agrees a deal with the London and North Western Railway Company to set up bookstalls at all their stations. This will be the foundation of the profitable W H Smith stationery and bookshop chain.
1848	UK [social customs]	Prince Albert and Queen Victoria's Christmas tree appears in the Illustrated London News, inspiring the custom among the middle classes.
1848	France [memoirs]	The French writer François-Auguste-René, vicomte de Chateaubriand, publishes the first part of his autobiographical Mémoires d'outre-tombe/Memoirs from Beyond the Grave.
1848	Germany [philosophy]	The German political philosophers Karl Marx and Friedrich Engels publish Manifest der Kommunistischen Partei/Manifesto of the Communist Party, one of the central works of Marxism. It contains the famous lines: ‘Workers of the world unite. You have nothing to lose but your chains.’
1848	France [photography]	French scientists Alexandre Becquerel and Abel Niépce de Saint-Victor produce the first colour photographs using coatings of silver chloride. They are unable to be fix the images.
1848	Scotland [physics]	Scottish physicist William Thomson (Lord Kelvin) devises the absolute temperature scale. He defines absolute zero as -273°C/-459.67°F, where the molecular energy of molecules is zero. He also defines the quantities currently used to describe magnetic forces: magnitude of magnetic flux, beta, and H the magnetizing force.
20 January 1848	Denmark, Germany [political events]	King Christian VIII of Denmark dies and is succeeded by his liberal son Frederick VII, who is nevertheless committed to retaining the duchies of Schleswig and Holstein despite their claims for independence.
24 January 1848	USA [natural resources]	The US prospector James Marshall discovers gold in the millrace at Sutter's Mill on the American River near Sacramento, California.
2 February 1848	USA, Mexico [wars]	The Treaty of Guadeloupe Hidalgo ends the Mexican-American War. By its terms, Mexico sells territory comprising the modern states of Texas, New Mexico, Arizona, Utah, Nevada, California, and western Colorado to the USA for a payment of $15 million.
24 February 1848	France [political events]	King Louis-Phillipe of France abdicates in favour of his grandson, Louis-Philippe-Albert, comte de Paris, but a Republican provisional government containing the socialist Louis Blanc is established under Alphonse de Lamartine.
3 March 1848	Hungary [revolution]	A revolution breaks out in Budapest and on 15 March the Hungarian diet (national assembly) is subsequently granted the reforms it advocated in March 1847, making it effectively independent under Austrian rule.
12 March - 15 March 1848	Austrian Empire [revolution]	A revolution in Vienna, the Austrian capital, begins with demonstrations by liberal students, inspired by the revolutions in Paris, France, and Budapest, Hungary.
14 March 1848	Papal States [law and government]	A constitution for the Papal States is promulgated reluctantly by Pope Pius IX, in response to the revolutions in the rest of Italy.
17 March 1848	Prussia [revolution]	Demonstrations in the Prussian capital, Berlin, begin a revolution in Prussia for political reform and the creation of a united Germany.
20 March 1848	India, UK [wars]	The Second Anglo-Sikh War begins in India, arising out of the Sikh aristocracy's discontent at British administration and the subsequent murder of two British officers.
22 March 1848	Sardinia-Piedmont, Austrian Empire [wars]	King Charles Albert of Sardinia-Piedmont declares war on Austria in an attempt to check Austrian influence and unify Italy under his leadership.
13 April 1848	Naples, Sicily, Italy [revolution]	Sicily, having revolted against the rule of the Bourbon King Ferdinand II of the Two Sicilies, declares itself independent of Naples.
2 May 1848	Prussia, Denmark, Germany [political events]	A Prussian force invades Denmark in support of the independent German government of the combined duchies of Schleswig and Holstein.
18 May 1848	Germany, Saxony [law and government]	A National Assembly composed of liberal delegates elected from all over Germany meets in Frankfurt and suspends the German Confederation prior to discussing a more unified organization of the German states.
7 June 1848	France [births and deaths]	Paul Gauguin, French post-Impressionist painter, born in Paris, France (–1903).
9 August 1848	Sardinia-Piedmont, Austrian Empire, Lombardy, Italy [revolution]	Following the decisive Piedmontese defeat at Custozza in the Veneto, an armistice is concluded between Austria and Sardinia-Piedmont at Vigevano, Lombardy, by which Sardinia-Piedmont gives up Lombardy and accepts the status quo as it existed in Italy before the revolutions.
12 August 1848	England [births and deaths]	George Stephenson, English engineer, inventor of the railway locomotive, dies in Chesterfield, Derbyshire, England (67).
26 August 1848	Denmark, Prussia, Germany [treaties]	The Truce of Malmö is made between Denmark and Prussia ending the war over the duchies of Schleswig and Holstein. The truce establishes an armistice that lasts for 17 months, during which Schleswig–Holstein is jointly administered by Austria and Prussia.
29 August 1848	UK, Orange Free State [colonization]	The Boers (Dutch settlers) in southern Africa are defeated at Boomplaats in the Orange Free State by British forces, and retire across the Vaal River, ensuring British sovereignty over the Orange River.
7 September 1848	Austrian Empire [legislation]	The feudal practice of serfdom, by which peasants are tied to the land and controlled by their landlords to whom they owe dues of service, is abolished in Austria.
12 September 1848	Switzerland [law and government]	Following the defeat of the Sonderbund, the armed league of the seven Catholic cantons, Switzerland adopts a new constitution by which the states become a federal union with strong central government.
17 September 1848	Austrian Empire [political events]	Count Josip Jellacic leads a Croat invasion of Hungary, disputing Magyar domination of the Habsburg monarchy's Slav peoples.
7 November 1848	USA [elections]	MexicanAmerican War hero Zachary Taylor is elected as US president and Millard Fillmore as vice-president.
2 December 1848	Austrian Empire [political events]	The mentally unstable emperor Ferdinand I of Austria abdicates in favour of his nephew Franz Josef I.
5 December 1848	Prussia [law and government]	The Prussian National Assembly is dissolved and a constitution is imposed that includes universal male suffrage, but the ultimate authority of King Frederick Wilhelm IV is maintained.
19 December 1848	England [births and deaths]	Emily Brontë, English novelist known for Wuthering Heights (1847), dies in Haworth, Yorkshire (now West Yorkshire), England (30).