Editing 1821 (section)

=== January–June ===
[[File:James Longstreet.jpg|thumb|right|110px|[[James Longstreet]]]]
* [[January 1]] – [[Francisco de Paula Milán]] Mexican officier of the [[Mexican Armed Forces|Mexican Army]] (d. 1883)
* [[January 2]] – [[Catherine Huggins]], British actor, singer, director and manager (d. 1887)
* [[January 8]]
** [[James Longstreet]], American Confederate general (d. 1904)
** [[W. H. L. Wallace]], American Civil War general (d. 1862)
* [[February 3]] – [[Elizabeth Blackwell]], first American female physician (d. 1910)
* [[February 11]] – [[Auguste Mariette|Auguste Edouard Mariette]], French Egyptologist (d. 1881)
* [[February 17]] – [[Lola Montez]], Irish-Spanish dancer, royal mistress (d. 1861)
* [[February 19]]
** [[Francis Preston Blair Jr.]], American politician, American Civil War officer (d. 1875)
** [[August Schleicher]], German linguist (d. 1868)
* [[March 1]] – [[Joseph Hubert Reinkens]], German [[Old Catholic Church|Old Catholic]] bishop (d. 1896)
* [[March 9]] – [[John Watts de Peyster]], American author, philanthropist, and soldier (d. 1907)
* [[March 12]] – Sir [[John Abbott]], 3rd [[Prime Minister of Canada]] (d. 1893)
* [[March 31]] – [[Henry Dunning Macleod]], Scottish economist (d. 1902)
* [[April 1]] – [[Princess Anka Obrenović]], Serbian princess (d. 1868)
* [[April 3]] – [[T. Pelham Dale|Fr. Thomas Pelham Dale]], English mystic (d. 1892)
* [[April 9]] – [[Charles Baudelaire]], French poet, writer (d. 1867)<ref>Charles Baudelaire, Richard Howard. ''Les Fleurs Du Mal''. David R. Godine Publisher, 1983, p.xxv. {{ISBN|0-87923-462-8}}, {{ISBN|978-0-87923-462-1}}.</ref> 
* [[April 12]] – [[Beauchamp Seymour, 1st Baron Alcester|Beauchamp Seymour]], British admiral (d. 1895)
* [[May 6]]
** [[Edmund Colhoun]], American admiral (d. 1897)
** [[Emilie Hammarskjöld]], Swedish-American musician (d. 1854)
* [[May 8]] – [[William Henry Vanderbilt]], American entrepreneur (d. 1885)
* [[May 16]] – [[Pafnuty Chebyshev]], Russian mathematician (d. 1894)
* [[May 17]] – [[Sebastian Kneipp]], German naturopath (d. 1897)
* [[May 18]] – [[Eduard von Pestel]], Prussian military officer and German general (d. 1908)
* [[May 24]] – [[Juan Bautista Topete]], Spanish admiral and politician (d. 1885)
* [[June 2]] – [[Ion C. Brătianu]], 2-Time Prime Minister of Romania (d. 1891)
* [[June 16]] – [[Old Tom Morris]], Scottish golfer (d. 1908)
* [[June 26]] – [[Bartolomé Mitre]], Argentine statesman, military figure, and author, 6th President of Argentina (d. 1906)