* 1812 – British forces under the command of the Duke of Wellington assault the fortress of Badajoz.

* 1812 – Alexander Herzen, Russian writer ( d. 1870 )

* 1812 – The Territory of Orleans becomes the 18th U. S. state under the name Louisiana.

* 1812 – Kaspar Hauser, German mystery boy ( d. 1833 )

* 1812 – War of 1812: The Battle of Fort Dearborn is fought between United States troops and Potawatomi at what is now Chicago, Illinois.

* 1812 – War of 1812: American General William Hull surrenders Fort Detroit without a fight to the British Army.

* 1812 – War of 1812: American frigate defeats the British frigate off the coast of Nova Scotia, Canada earning her nickname " Old Ironsides ".

He was one of the founders of the Geological Society of London in 1807 and was its honorary secretary in 1812 – 1817.

Andrew Johnson was born in Raleigh, North Carolina, to Jacob Johnson ( 1778 – 1812 ) and Mary (" Polly ") McDonough ( 1783 – 1856 ), a seamstress and the daughter of Andrew McDonough.

* 1812 – Peninsula War: A coalition of Spanish, British, and Portuguese forces succeed in lifting the two-and-a-half-year-long Siege of Cádiz.

* Alfonso Sanz y Martínez de Arizala ( 28 January 1880, Madrid – 1970 ), married in 1922 to María de Guadalupe de Limantour y Mariscal ( d. 1977, Marbella ), daughter of Julio de Limantour y Marquet ( 17 June 1863, Mexico City – 11 October 1909, Mexico City ) and wife Elena Mariscal y ..., paternal granddaughter of French Joseph Yves de Limantour y Rence de la Pagame ( 1812, Ploemeur – 1885, Mexico City ) and wife Adèle Marquet y Cabannes ( 1820, Bordeaux –?

* 1768 – Joseph Dennie, American author and journalist ( d. 1812 )

* 1812 – Agoston Haraszthy Hungarian-American traveler, writer, and winemaker, founded Buena Vista Winery ( d. 1869 )

* 1812 – Peninsular War: French troops engage British-Portuguese forces in the Battle of Majadahonda.

* 1748 – Joseph Schuster, German composer ( d. 1812 )

* 1813 – War of 1812: United States troops capture the capital of Upper Canada in the Battle of York ( present day Toronto, Canada ).

* Principality of Anhalt-Bernburg-Schaumburg-Hoym: 1718 – 1812

István Bató ( 1812 – 1890 ) was a prominent citizen of the Northern Hungarian city of Miskolc in the 19th century.

János Garay ( October 10, 1812 – November 5, 1853 ) was a Hungarian poet and author, was born in Szekszárd, Tolna County.

* 1812 – Alexander Hamilton Stephens, American politician, Vice President of the Confederate States of America and 50th Governor of Georgia ( d. 1883 )

* 1812 – Henry Wilson, American politician 18th Vice President of the United States ( d. 1875 )

* 1739 – George Clinton, American politician, 4th Vice President of the United States ( d. 1812 )

His father, Archibald Stuart, was a War of 1812 veteran, slaveholder, attorney, and Democratic politician who represented Patrick County in both houses of the Virginia General Assembly, and also served one term in the United States House of Representatives.

* 1812 – Herschel Vespasian Johnson, American politician, 41st Governor of Georgia ( d. 1880 )

* September 3 – William W. Snow, American politician ( b. 1812 )

* December 8 – William Fraser Tolmie, Scottish-Canadian scientist and politician ( b. 1812 )

* July 26 – George Clinton, American soldier and politician ( d. 1812 )

* June 25 – John Horne Tooke, English politician and philologist ( d. 1812 )

* Samuel Laing ( science writer ) ( 1812 – 1897 ), son of the above, a businessman, politician and writer on modern science

* Charles John Canning, 1st Earl Canning ( 1812 – 1862 ), politician and Governor-General of India

* James Andrew Broun-Ramsay, 1st Marquess of Dalhousie ( 1812 – 1860 ), politician and Governor-General of India

George Clinton ( July 26, 1739 April 20, 1812 ) was an American soldier and politician, considered one of the Founding Fathers of the United States.

* Sir Robert Heron, 2nd Baronet ( 1765 – 1854 ), British Whig politician, Member of Parliament ( MP ) for Great Grimsby 1812 – 18 and Peterborough 1819 – 47

* Alphonse Vandenpeereboom ( 1812 – 1884 ), politician, minister

Joel Barlow ( March 24, 1754 – December 26, 1812 ) was an American poet, diplomat, and politician.

Constantine Henry Phipps, 1st Marquess of Normanby KG GCB GCH, PC ( 15 May 1797 – 28 July 1863 ), styled Viscount Normanby between 1812 and 1831 and known as The Earl of Mulgrave between 1831 and 1838, was a British Whig politician and author.

* Charles Moore ( English politician ) ( 1771 – 1826 ), English politician, Member of Parliament 1799 – 1802, 1802 – 1806 and 1807 – 1812

* Thomas Hamilton, 9th Earl of Haddington ( 1780 – 1858 ), Scottish / English politician ; Conservative MP ( 1802 – 1812 and 1814 – 1827 )

* Georges-Charles de Heeckeren d ' Anthès ( 1812 – 1895 ), politician, killer of Alexander Pushkin in a duel

* George D. Beers ( 1812 – 1880 ), New York politician

Robert Banks Jenkinson, 2nd Earl of Liverpool KG PC ( 7 June 1770 – 4 December 1828 ) was a British politician and Prime Minister of the United Kingdom ( 1812 – 27 ).

Robert Nelles, a politician and later lieutenant-colonel in the War of 1812, was one of the main founders of the town.