1820s

From top left, clockwise: Ludwig van Beethoven re-emerged as a popular composer during this decade, when his iconic Symphony No. 9 is first performed in Vienna in 1824. The First Industrial Revolution achieves peak momentum for the West, as depicted in this engraving of a textile factory operating in Manchester, arguably England's industrial hub of the 19th century; The world's oldest photograph was taken in 1826, as seen above. The decade was the start of daguerreotype development – an instrument used for motion-picture capturing and was a precursor instrument to the camera; South American wars of independence were on full swing, as countries like Brazil, Bolivia, Peru, and Uruguay gained their independence at this era; a turning point for regional politics, and heavily influenced South America's contemporary socio-political conditions; Crowds gather to witness the opening of the world's first railway – the Stockton and Darlington Railway – as it formally commenced in 1825; The world's first electric motor was created by Hungarian engineer Ányos Jedlik. His invention would drive to form modern-day knowledge and utilization of electricity, and forged way for studies on electrochemistry and engineering to grow; Antarctica was discovered and explored for the first time. Its inaugural expedition into continental waters was led by a Russian crew headed by Fabian Gottlieb von Bellingshausen, in 1819 to 1821; As European colonialism began gaining ground in Africa and Asia, opposition from affected/exploited societies resulted, with wars such as the Java War.

The 1820s was a decade of the Gregorian calendar that began on January 1, 1820, and ended on December 31, 1829.

It saw the rise of the First Industrial Revolution. Photography, rail transport, and the textile industry were among those that largely developed and grew prominent over the decade, as technology advanced significantly. European colonialism began gaining ground in Africa and Asia, and trade with the Qing Dynasty began to open up more towards foreign traders, particularly those from Europe. As European imperialism gained momentum, opposition from affected/exploited societies resulted, with wars such as the Java War and the Greek War of Independence. Resistance in the form of separatism and nationalism (particularly in the Spanish American wars of independence) led to the independence of many countries around the world, such as Brazil, Peru, and Bolivia.