| 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. |
| August 1860 - June 1861 | Australia [exploration] | Irish settler Robert Burke and English surveyor William Wills lead an expedition out of Victoria to cross Australia from south to north. The four-man advance party turns back only a few miles from the coast of the Gulf of Carpentaria and misses the support party in the desert of Cooper Creek; only one member of the expedition, John King, survives. |
| 1861 | UK [everyday life] | Isabella Beeton writes her Book of Household Management, a comprehensive domestic manual for housewives and mothers in Britain based on her articles in the Englishwoman's Domestic Magazine. |
| 1861 | USA [media and communication] | A telegraph wire is strung across the USA between New York City and San Francisco, California; it follows the route of the pony express which it now makes redundant. |
| 1861 | Russian Empire, USA, UK, Italy [statistics and demography] | The population of Russia is 76 million, 32 million in the USA, 23.1 million in Britain, 5.7 million in Ireland, and 25 million in Italy. |
| 1861–1870 | USA, UK, Ireland [statistics and demography] | Emigration to the USA from Britain totals 606,896; from Ireland it is 435,779. |
| 1861 | UK [statistics and demography] | The population of Britain is over 23 million. |
| 1861 | UK [taxation] | The withdrawal of the tax on paper leads to a drop in newspaper prices in Britain. |
| 1861 | France [transport] | French inventor Pierre Michaux and his son Ernst construct the first successful bicycle with pedals. The pedals are attached to the front wheel, and because it has steel tyres and no springs it is called the ‘bone-shaker’. |
| 1861 | Germany [earth sciences] | The first Archaeopteryx feather is found in upper Jurassic limestones of Solnhofen, Bavaria (now in Germany). Archaeopteryx has many reptilian features and is 55–190 million years old. It is still the oldest known bird. |
| 1861 | Belgium [chemistry] | Belgian chemist Ernest Solvay patents a method for the economic production of sodium carbonate, washing soda, from sodium chloride, ammonia, and carbon dioxide. |
| 1861–1865 | USA [economic conditions] | The USA, or the North, has a booming economy during the Civil War as production and profits soar. There is inflation, too; prices rise 117% and wages rise just 43%. |
| 2 January 1861 | Prussia [political events] | King Frederick Wilhelm IV of Prussia dies and is succeeded by his brother Wilhelm I. |
| February 1861 | Confederate States of America [political events] | South Carolina, Mississippi, Florida, Alabama, Georgia, and Louisiana form the Confederate States of America in a constitutional convention at Montgomery, Alabama. |
| 3 March 1861 | Russian Empire [serfdom] | An edict emancipating serfs on private Russian estates is proclaimed, ending the medieval practice which ties them to their landlords. |
| 17 March 1861 | Italy [political events] | The kingdom of Italy is formally proclaimed by the first Italian parliament. King Victor Emmanuel is proclaimed king. |
| 12 April - 13 April 1861 | USA [American Civil War (1861–65)] | Confederate forces take the federal garrison of Fort Sumter, Charleston, South Carolina, after a 40-hour bombardment, marking the outbreak of the American Civil War. |
| 19 May 1861 | Australia [births and deaths] | Nellie Melba, Australian soprano, born in Richmond, near Melbourne, Australia (–1931). |
| 25 June 1861 | Ottoman Empire [political events] | Sultan Abdul Mejid of the Ottoman Empire dies and is succeeded by his brother Abdul Aziz. |
| 30 June 1861 | England, Florence [births and deaths] | Elizabeth Barrett Browning, English poet and wife of the English poet Robert Browning, dies in Florence, Italy (55). |
| 21 July 1861 | USA [American Civil War (1861–65)] | The Confederates gain an indecisive victory over the Union army in the Battle of Bull Run in Virginia, the first major military engagement of the American Civil War. |
| 11 November 1861 | Portugal [political events] | King Pedro V of Portugal dies and is succeeded by Louis I. |
