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