| 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. |
| 1821–1830 | USA, UK, Ireland [statistics and demography] | Emigration to the USA from Britain is 27,489, and from Ireland, 54,338. |
| 1827–1838 | Ireland, Germany, USA [statistics and demography] | A period of Irish and German migration to the USA begins due to a severe winter in 1829, increased legislation against German Jews, economic stress in Ireland, and Irish factionalism. |
| 1827–1838 | USA [zoology] | US ornithologist John James Audubon publishes the first volume of his multi-volume work Birds of America. |
| 1827 | UK [family planning] | English clergyman Thomas Malthus's sixth edition of his 1798 pamphlet An Essay on the Principle of Population expresses the view that the poor laws only encourage large families; he encourages people to marry late and to exercise ‘moral restrain’ as a means of economic control. |
| 1827 | USA [everyday life] | The first Mardi Gras celebrations take place in New Orleans, Louisiana, introduced by French students. |
| 1827 | Germany [maths] | German mathematician Carl Friedrich Gauss introduces the subject of differential geometry that describes features of surfaces by analyzing curves that lie on it – the intrinsic-surface theory. |
| 1827 | France [painting] | The French artist Eugène Delacroix paints The Death of Sardanapalus. |
| 1827 | Germany [physics] | German physicist Georg Ohm formulates Ohm's law, which states that the current flowing through an electric circuit is directly proportional to the voltage, and indirectly proportional to the resistance. |
| 1827 | Scotland [physics] | Scottish botanist Robert Brown is the first to report the observation of the continuous motion of tiny particles in a liquid solution – now known as Brownian motion. |
| 1827 | Germany [poetry] | The German poet Heinrich Heine publishes his poetry collection Buch der Lieder/Book of Songs. |
| 28 February 1827 | USA [railways] | The Baltimore and Ohio Railroad becomes the first railway in the USA to be chartered to carry freight and passengers. The railway is built to compete with the Erie Canal, which is taking business away from Baltimore, Maryland. |
| 26 March 1827 | Germany, Austria [births and deaths] | Ludwig van Beethoven, German classical Romantic composer, dies in Vienna, Austria (56). |
| 10 April 1827 | UK [law and government] | The Tory foreign secretary, George Canning, becomes prime minister of Britain, forming a government of liberal Tories and moderate Whigs. |
| 6 July 1827 | Russian Empire, UK, France, Greece, Ottoman Empire [treaties] | The Treaty of London is signed by which Russia, Britain, and France agree to recognize the autonomy of Greece and so force Sultan Mahmud II of the Ottoman Empire to make peace with the Greeks. |
