1840s

The 1840s was the decade that began on January 1, 1840 and ended on December 31, 1849. It is distinct from the decade known as the '''185st decade''' which began on January 1, 1841 and ended on December 31, 1850.

 Events 
 Treaty of Nanking between China and the United Kingdom(1842)
 Irish Potato Famine(1845–1848)
 Mexican-American War (1846–1848)
 The Communist Manifesto (1848)is published
 European Revolutions of 1848 (1848)
 California Gold Rush (1849)

 World leaders 
 Emperor Ferdinand I (Austria)
 Chancellor Klemens Wenzel von Metternich (Austria)
 Emperor Franz Josef (Austria-Hungary)
 King Louis-Philippe (July Monarchy France)
 Frederick William IV of Prussia (Prussia)
 Pope Gregory XVI
 Pope Pius IX
 Emperor Nicholas I (Russia)
 Queen Isabella II (Spain)
 Queen Victoria (United Kingdom of Great Britain and Ireland)
 Prime Minister Lord Melbourne (United Kingdom)
 Prime Minister Sir Robert Peel (United Kingdom)
 Prime Minister Lord John Russell (United Kingdom)
 President Martin Van Buren (United States)
 President William Henry Harrison (United States)
 President John Tyler (United States)
 President James Knox Polk (United States)
 President Zachary Taylor (United States)
 Sultan Abd-ul-Mejid I (Ottoman Empire)
 Shahs of Persia (Qajar dynasty)
 Mohammad Shah Qajar, (b. 1810 – d. 1848) Shah from 1834 to 1848
 Nasser-al-Din Shah, 1848–1896

 Births 
 Edvard Grieg (1843)
 Wyatt Earp (1848)

 Deaths 
 Edgar Allan Poe (1849)