| 1799–1825 | [maths] | The French mathematician and physicist Pierre-Simon Laplace publishes the five-volume Traité de mécanique céleste/Celestial Mechanics, which applies calculus to the motions of celestial bodies and Isaac Newton's theories of the Solar System to show how its stability is implicit in the law of gravitation. |
| 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. |
| c. 1818 | Germany [painting] | The German artist Caspar David Friedrich paints Wanderer above the Sea of Fog. |
| 1818 | England [poetry] | The English poet John Keats publishes Endymion: A Poetic Romance. |
| 1818 | Scotland [fiction] | The Scottish poet and novelist Walter Scott publishes the novels Heart of Midlothian and Rob Roy. |
| 1818 | England [fiction] | The English writer Mary Wollstonecraft Shelley publishes the Gothic novel Frankenstein, or the Modern Prometheus. The novel is published anonymously, although the authorship becomes known in 1823. |
| 1818 | England [fiction] | Two novels by the English writer Jane Austen are published posthumously: Northanger Abbey (an early Austen novel that makes fun of the taste for gothic novels) and Persuasion. |
| 6 January 1818 | UK, India [treaties] | Under the Treaty of Mundoseer, the dominions of the Maratha Holkar dynasty of Indore are combined administratively with the Rajput states of northwest India, and come under British protection. |
| 12 February 1818 | Chile, Spain [decolonization] | The Spanish colony of Chile proclaims itself independent. |
| 6 April 1818 | Germany, UK [transport] | German inventor Karl von Drais de Sauerbrun exhibits his draisienne, a two-wheeled bicycle propelled by pushing the feet along the ground, with a padded seat and a swivelling steering mechanism. It becomes popular in Britain the following year and is known as the ‘hobby horse’. |
| 29 April 1818 | Russia [births and deaths] | Alexander II, Tsar of Russia 1855–81 who is responsible for emancipating the Russian serfs, born in Moscow, Russia (–1881). |
| 5 May 1818 | Prussia [births and deaths] | Karl Marx, Prussian political theorist, economist, and sociologist whose ideas formed the basis of communism, born in Trier, Prussia (–1883). |
| 2 June 1818 | UK, India [colonization] | The leader of the Maratha confederacy in India, Baji Rao, the Peshwa of Poona, surrenders to the British forces of Francis Rawdon-Hastings, Marquess of Hastings and governor-general of Bengal. Britain annexes the Peshwa's lands, effectively destroying the Maratha Confederacy, the last significant rival to British domination of the subcontinent. |
| 30 July 1818 | England [births and deaths] | Emily Brontë, English novelist known for Wuthering Heights (1847), born in Thornton, Yorkshire (now West Yorkshire), England (–1848). |
| 22 August 1818 | England [births and deaths] | Warren Hastings, British statesman and the first governor general of Bengal (most of British India) (1774), dies in Daylesford, Oxfordshire, England (86). |
| 21 December 1818 | France [administration] | Armand du Plessis, duc de Richelieu, resigns as prime minister in France and is succeeded by Elie, duc de Decazes, after the October elections show increasing support for the left. |
| 24 December 1818 | England [births and deaths] | James Prescott Joule, English physicist who demonstrated that the various forms of energy can be transformed one into another, born in Salford, Lancashire, England (–1889). |
