1840s

{| align=right cellpadding=3 id=toc style="margin-left: 15px;"\n|- \n| align="center" | Centuries:
18th century - 19th century - 20th century

---

\n|-\n| align="center" colspan=2 | Decades:
1810s 1820s 1830s - 1840s - 1850s 1860s 1870s\n|- \n| align="center" colspan=2 | Years:
1840 1841 1842 1843 1844 1845 1846 1847 1848 1849\n|} \nEvents and Trends\n*First signing of the Treaty of Waitangi (Te Tiriti o Waitangi) on February 6, 1840 at Waitangi New Zealand. The treaty between the British Crown and Maori made New Zealand a British colony and is considered the founding point of modern New Zealand. \n*Introduction of the postage stamp. The first of them is Penny Black, issued by the United Kingdom on May 1, 1840.\n*Mexican-American War (1846 - 1848) fought between Mexico and the United States of America. The later emerges victorious and gains undisputed control over Texas while annexing portions of Arizona, California and New Mexico.\n* Wave of revolutions in Europe. Collectively known as the Revolution of 1848.\n* Karl Marx writes The Communist Manifesto, first published on February 21, 1848. World Leaders\n* Emperor Ferdinand I (Austria)\n* Chancellor Klemens Wenzel von Metternich (Austria)\n* Emperor Franz Josef (Austria-Hungary)\n* King Louis-Philippe (France)\n* Pope Gregory XVI\n* Pope Pius IX\n* Emperor Nicholas I (Russia)\n* Queen Victoria (United Kingdom)\n* Prime Minister Lord Melbourne (United Kingdom)\n* Prime Minister Sir Robert Peel (United Kingdom)\n* Prime Minister Lord John Russell (United Kingdom)\n* President Martin Van Buren (United States)\n* President John Tyler (United States)\n* President James Knox Polk (United States) \n\n\n\n\n\n\n\n\n\n\n\n\n\n