Historical
1820: Liberia - Liberia founded by the American Colonization Society for freed American slaves
1820: United States - Missouri Compromise admits Missouri as a slave state and Maine as a free state
1821-1830: Greece, Turkey - Greece becomes the first country to break away from the Ottoman Empire after the Greek War of Independence
1821: Mexico, Spain - Mexico gains Independence from Spain with the Treaty of Cordoba
1821: Peru, Spain - Peru declares Its Independence from Spain
1822-1823: Mexico - First Mexican Empire, as the first post-independent Mexican government, ruled by Emperor Agustin I of Mexico
1822: Brazil, Portugal - Prince Pedro of Portugal proclaimed the Brazilian Independence on September 7, on December 1, he was crowned as Emperor Dom Pedro I of Brazil
1823-1887: England, Burma - The British Empire annexed Burma (now also called Myanmar) after three Anglo-Burmese Wars
1825-1828: Argentina, Brazil, Uruguay - The Argentina-Brazil War results in the Independence of Uruguay
1825: United States - Erie Canal opened connecting the Great Lakes to the Atlantic Ocean
1826-1828: Russia, Iran - After the final Russo-Persian War, the Persian Empire took back territory lost to Russia from the previous war
1827: England - Death of William Blake, an English poet, painter, and printmaker who Influenced literature
1828-1829: Russia, Turkey - Russo-Turkish War (ninth of ten), Russian victory
1830: Belgium, Netherlands - The Belgian Revolution in the United Kingdom of the Netherlands led to the creation of Belgium
1830: Colombia, Venezuela, Ecuador - Greater Colombia dissolved and the nations of Colombia (including modern-day Panama), Ecuador, and Venezuela took Its place
1830: France - July Revolution in France
1830: Poland, Russia - November Uprising in Poland against Russia
1830: United States - The Church of Jesus Christ of Latter Day Saints is established on April 6, 1830
1831-33: Egypt - Egyptian-Ottoman War
1831: France, Algeria - France Invades and occupies Algeria
1833-1876: Spain - Carlist Wars in Spain
1833: England - Slavery Abolition Act bans slavery throughout the British Empire
1834-1859: Russia - Rebellion led by Imam Shamil in Russian-occupied Caucasus
1834: Germany - The German Customs Union is formed
1834: Spain - Spanish Inquisition officially ends
1835-1836: United States, Mexico - The Texas Revolution in Mexico resulted in the short-lived Republic of Texas
1836: United States, Mexico - The Battle of the Alamo
1837-1838: Canada - Rebellions of 1837 in Canada
1837-1901: England - Reign of Queen Victoria is considered the apex of the British Empire and is referred to as the Victorian era
1838-1840: Central America - Civil war in the Federal Republic of Central America led to the foundings of Guatemala, El Salvador, Honduras, Nicaragua, and Costa Rica
1839-1851: Uruguay - Uruguayan Civil War
1839-1860: France, England, United States, Russia, China - After two Opium Wars, France, the United Kingdom, the United States and Russia gained many concessions from China resulting in the decline of the Qing Dynasty
1840: New Zealand, England - New Zealand is founded, as the Treaty of Waitangi is signed by the Ma-ori and British
1844: Haiti - Dominican War of Independence from Haiti
1844: Iran - Persian Prophet the Bab announces his revelation on May 23, founding Babism, he announced to the world of the coming of "He whom God shall make manifest", he is considered the forerunner of Baha u llah, the founder of the Baha I Faith
1844: United States - First publicly funded telegraph line in the world, It is between Baltimore and Washington and sends demonstration message on May 24, ushering in the age of the telegraph, this message read "What hath God wrought?" (Bible, Numbers 23:23)
1844: United States - Millerite (followers of the teachings of William Miller) movement awaits the Second Advent of Jesus Christ on October 22, the non-appearance of Christ becomes known as the Great Disappointment
1845-1846: Pakistan - First Anglo-Sikh War in Punjab (Pakistan) between the Sikh Empire and the British East India Company
1845-1849: Ireland - The Irish Potato Famine led to the Irish diaspora
1845-1872: New Zealand - The New Zealand Land Wars
1845: Tonga - Unification of the Kingdom of Tonga under Ta-ufa?a-hau (King George Tupou I)
1846-1847: United States - Mormon migration to Utah
1846-1848: United States, Mexico - The Mexican-American War leads to cession by Mexico of much of the modern-day Southwestern United States
1847-1901: Mexico - The Caste War of Yucatan
1848-1849: Pakistan - Second Anglo-Sikh War in Punjab (Pakistan) between the Sikh Empire and the British East India Company, this war basically ends the Sikh Empire
1848-1858: United States - California Gold Rush
1848: Europe - Revolutions of 1848 in Europe as some type of revolution occurred in most all European countries (except England and the Netherlands), the revolutions were quickly put down as they were mostly unorganized peasants
1848: Russia - The Communist Manifesto published
1848: United States - Seneca Falls Convention is the first rights for women convention in the United States and leads to the battle for suffrage and legal rights for women
1850: Europe - The Little Ice Age ends around this time