Decades: 1770s 1780s 1790s 1800s 1810s - 1820s - 1830s 1840s 1850s 1860s 1870s
Years: 1816 1817 1818 1819 1820 - 1821 - 1822 1823 1824 1825 1826
February 23 - The Philadelphia College of Apothecaries founds the first pharmacy college.
March 25 - Greece declares its independence from the Ottoman Empire, beginning the Greek War of Independence.
July 10 - The United States takes possession of its newly-bought territory of Florida from Spain.
July 28 - Peru declares independence from Spain.
August 4 - Atkinson & Alexander publish the Saturday Evening Post for the first time as a weekly newspaper.
September 27 - Mexico gains its independence from Spain.
August 10 - Missouri is admitted as the 24th U.S. state.
November 16 - American Old West: Missouri trader William Becknell arrives in Santa Fe, New Mexico and sells his merchandise for a huge profit (he immediately planned to return the following year over a route that became known as the Santa Fe Trail).
In the first known obscenity case in the United States, a Massachusetts court outlawed the John Cleland novel, Fanny Hill . The publisher, Peter Holmes, was convicted for printing a "lewd and obscene" novel.
Year in topic
1821 in literature
1821 in science
January 8 - James Longstreet, Confederate General († 1904)
February 3 - Elizabeth Blackwell, first female physician in the United States († 1910)
February 11 - Hermann Allmers, writer († 1902)
February 11 - Auguste Edouard Mariette, French Egyptologist who dug out the Sphinx († 1881)
February 17 - Eliza Rosanna Gilbert, better known as Lola Montez († 1861)
February 19 - August Schleicher, German linguist († 1868)
April 9 - Charles-Pierre Baudelaire, French poet and writer († 1867)
May 8 - Jean Henri Dunant, founder of the Red Cross and recipient of the Nobel Prize in peace 1901 († 1910)
May 17 - Sebastian Kneipp, naturopathist († 1897)
July 18 - Pauline Garcia-Viardot, mezzo-soprano and composer († 1910)
August 10 - Jay Cooke, financier († 1905)
October 13 - Rudolf Virchow, German doctor, pathologist, biologist, and politician († 1902)
November 11 - Fyodor Dostoevsky, Russian writer († 1881)
January 4 - Elizabeth Ann Seton, American saint (* 1774)
February 23 - John Keats, British poet, dies in Rome (* 1795)
March 13 - John Hunter - second governor of New South Wales (* 1737)
May 5 - Napoleon I of France (* 1769)
May 19 - Camille Jordan, French politician (* 1771)
Heads of states
Ottoman Empire - Mahmud II Sultan of the Ottoman Empire (1808-1839)
Prussia - Frederick William III King of Prussia (1797-1840)
Russia - Alexander I Tsar of Russia (1801-1825)