He returned to politics to oppose the pro-slavery Kansas – Nebraska Act ( 1854 ); this law repealed the slavery-restricting Missouri Compromise ( 1820 ).

Percy Bysshe Shelley composed a " Hymn of Apollo " ( 1820 ), and the god's instruction of the Muses formed the subject of Igor Stravinsky's Apollon musagète ( 1927 – 1928 ).

Causes include controversy over admitting Missouri as a slave state in 1820, the acquisition of Texas as a slave state in 1845 and the status of slavery in western territories won as a result of the Mexican – American War and the resulting Compromise of 1850.

* 1820 – Nadar, French photographer, caricaturist, journalist, novelist and balloonist ( d. 1910 )

* 1820 – Alexander Ypsilantis is declared leader of Filiki Eteria, a secret organization to overthrow Ottoman rule over Greece.

* 1820 – George Grove, English historian ( d. 1900 )

* 1820 – John Tyndall, British physicist ( d. 1893 )

* 1890 – David Wilber, American politician ( b. 1820 )

* 1751 – Wilhelmina of Prussia, Princess of Orange ( d. 1820 )

* 1820 – Andrew Rainsford Wetmore, Canadian politician ( d. 1892 )

* 1820 – Constitutionalist insurrection at Oporto, Portugal.

* 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 –?

* 1771 – Karl Philipp Fürst zu Schwarzenberg, Austrian field marshal ( d. 1820 )

* 1820 – Alexander Cartwright, American inventor of Baseball ( d. 1892 )

Anne Brontë (; 17 January 1820 – 28 May 1849 ) was a British novelist and poet, the youngest member of the Brontë literary family.

Four more children followed: Charlotte, ( 1816 – 1855 ), Patrick Branwell ( 1817 – 1848 ), Emily, ( 1818 – 1848 ) and Anne ( 1820 – 1849 ).

* 1899 – Joseph Wolf, German artist ( b. 1820 )

* Daniel Boone ( November 2, 1734 October 22 – September 26, 1820 ) was an American pioneer, explorer, and frontiersman whose frontier exploits made him one of the first folk heroes of the United States.

* 1820 – The Venus de Milo is discovered on the Aegean island of Melos.

In 1819 – 1820, Johann Baptist von Spix and Carl Friedrich Philipp von Martius were engaged in an expedition to Brazil, and on their return to Europe, amongst other collections of natural objects they brought home an important set of the fresh water fish of Brazil, and especially of the Amazon River.

The earliest galvanometer was reported by Johann Schweigger at the University of Halle on 16 September 1820.

The first white man known to arrive was a German, Johann Schoonover, who lived for a short time on the creek later named for him to trade with the Indians, about 1820.

The only interruptions occurred in 1813-1814, occasioned by the German War of Liberation ( War of the Sixth Coalition ), during which the university was closed, and those occasioned by two prolonged literary tours, first in 1820 to Paris, London and Oxford with his colleague Johann Karl Thilo ( 1794 – 1853 ) for the examination of rare oriental manuscripts, and in 1835 to England and the Netherlands in connection with his Phoenician studies.

Johann Joachim Eschenburg ( December 7, 1743 – February 29, 1820 ) was a German critic and literary historian.

The islands were named the Gilbert Islands in 1820 by a Russian admiral, Johann von Krusenstern, and French captain Louis Duperrey, after a British captain, Thomas Gilbert, who crossed the archipelago in 1788.

The Zugspitze was first conquered on 27 August 1820 by Josef Naus, his survey assistant, Maier, and mountain guide, Johann Georg Tauschl.

The first recorded ascent of the Zugspitze was achieved on 27 August 1820 by Lieutenant Josef Naus and mountain guide, Johann Georg Tauschl together with Naus ' survey assistant and batman ( servant ), Maier.

The son of Joseph Franz Weigl ( 1740 – 1820 ), the principal cellist in the orchestra of the Esterházy family, he was born in Eisenstadt and studied music under Johann Georg Albrechtsberger and Antonio Salieri.

While residing in Switzerland, he became impressed with what is now called the Pestalozzi School System, from Swiss pedagogist Johann Heinrich Pestalozzi ( 1746 – 1827 ) in France during the Napoleonic ephemeral Empire and then in Alicante, Spain, during the three years, between 1820 and 1823, known as the Constitutional Period.

******* Johann Michael Bach III ( 1745 – 1820 )-the music theorist

The disease is named after Eduard Heinrich Henoch ( 1820 – 1910 ), a German pediatrician, and his teacher Johann Lukas Schönlein ( 1793 – 1864 ), who described it in the 1860s.

As of 1820 he was on friendly terms with Johann Wolfgang von Goethe.

The decrees were the subject of Johann Joseph von Görres ' pamphlet Teutschland Deutschland und die Revolution ( Germany and the Revolution ) ( 1820 ), in which he concluded that it was both impossible and undesirable to repress the free utterance of public opinion by reactionary measures.

* Johann Christoph Georg Schiedmayer (* 1740 ; † 1820 ), master joiner, builder of organs and other music instruments

He hosted and entertained foreign naturalists and scientists, such as Johann Baptist von Spix ( 1781-1826 ) and Carl Friedrich Philipp von Martius ( 1794-1868 ), and explored the flora, fauna and geography of the province of Minas Gerais with French naturalist Augustin Saint-Hilaire from 1813 to 1820.

* Amalie Hofer, née Weissenrieder ( 1820 – 1872 ), wife of Johann Hofer, Forty-Eighters

: To be distinguished from Johann Michael Bach ( 1745 – 1820 )

He is sometimes referred to as the " Gehrener Bach " to distinguish him from the " Wuppertaler Bach ", Johann Michael Bach ( 1745 – 1820 ).

* Johann Nordmann ( 1820 – 1887 ), an Austrian journalist and travel writer

His collected works were published in Leipzig in eight volumes ( 1811 – 1839 ), with a biography by Johann E. von Gruner in volume 8 ( 1820 ), and again in 1856.

According to the dating up to now accepted by the majority of Czech authors, Božena Němcová was born in 1820 as Barbara Pankel ( or Barbora Panklová according to the usual Czech name-giving for women ) in Vienna as a daughter of Johann Pankel from Lower Austria and Teresie Novotná, a maid of Bohemian origin.