The 19th century lasted from 1801 to 1900 in the Gregorian calendar (using the Common Era system of year numbering). Common usage sometimes regards it as lasting from 1800 to 1899, but this is considered incorrect due to the nonexistence of a "Year Zero" before AD 1. The 19th century is also sometimes known as the eighteen hundreds (1800s), referring to the latter usage. Decades are almost always considered as starting with the "0" year and named accordingly ("1890s", etc.), so the first decade of a century technically overlaps back into the preceding one.
The rebellion of Greece begins in 1821 which ultimately leads to its independence
Belgium becomes independent in 1830 after a massive uprising against the Dutch. Leopold becomes the first king of Belgium. Belgium will be the second industrial power in the world by the middle of the 19th century.
Leopold II, son of Leopold, becomes the second king of Belgium. He buys the gigantic territory of Congo in Africa with his own fortune and will later (1908) offer it to Belgium.
Gold is discovered in several places in Australia and New Zealand and throughout the west of the United States, leading to huge increases in national wealth and encouraging mass migration of free settlers there.
The quick defeat of Spain by the United States in 1898, in the Spanish-American War, removes Spain from the list of major world powers for good and gives rise to the United States as a major world military power.
The electric telegraph and undersea cables make instant global communication possible for the first time.
Postage Stamps and diamond-shaped paper sheets which folded to form envelopes for carrying letters devised and introduced in Britain, and soon thereafter in many other countries, leading to establishment of the Universal Postal Union.
The Taiping Rebellion, from 1851 to 1864, a conflict between Imperial China and the followers of a Hakka self-proclaimed mystic and Christian convert Hong Xiuquan, took the lives of about 20 million people.
Manufactured goods become widely available by mail order
