- Sep 6 Carl Ferdinand Pohl, German-Austrian music historian and composer, born in Darmstadt, Hesse, Germany (d. 1887)
- Sep 6 Nicolae Filimon, Romanian writer and critic (Ciocoii Vechi Si Noi), born in Bucharest, Romania (d. 1865)
- Sep 6 William Starke Rosecrans, American inventor, politician and US Army General (Union Army), born in Delaware County, Ohio (d. 1898)
- Sep 7 Adriaan van Bevervoorde, Dutch journalist (History of Holland), born in Groningen, Netherlands (d. 1851)
- Sep 7 Thomas A. Hendricks, 21st Vice President of the United States (D), born in Fultonham, Ohio (d. 1885)
- Sep 9 Martin Luther Smith, American Major General (Confederate Army), born in Danby, New York (d. 1866)
Clara Schumann (1819-1896)
Sep 13 German pianist and composer of the Romantic era, born in Leipzig, Germany
- Sep 14 Henry Jackson Hunt, American Brevet Major General (Union Army), born in Detroit, Michigan (d. 1889)
- Sep 17 Leon Foucault, French physicist whose pendulum proved that the Earth rotates, born in Paris (d. 1868)
- Sep 17 Marthinus Wessels Pretorius, 1st president of the Republic South Africa, born in Graaff Reinet, Cape Colony (d. 1901)
- Sep 21 Louise Marie Thérèse of Artois, Duchess of Parma and Piacenza, born in Élysée Palace, Paris, France (d. 1864)
- Sep 22 Wilhelm Wattenbach, German historian (d. 1897)
- Sep 23 Hippolyte Fizeau, French physicist (d. 1896)
- Sep 28 Jacob Gijsbert de Hoop Scheffer, Dutch vicar and theologian, born in The Hague, Netherlands (d. 1893)