- Apr 4 Charles Devens Jr, American lawyer, jurist, statesman and Brevet Major General (Union Army), born in Charlestown, Boston, Massachusetts (d. 1891)
- Apr 5 Nadar [Félix Tournachon], French photographer and balloonist, took the first aerial photograph, born in Paris (d. 1910)
- Apr 14 Harry T. Hays, American Brigadier General (Confederate Army), born in Wilson County, Tennessee (d. 1876)
Alexander Cartwright (1820-1892)
Apr 17 American Baseball HOF pioneer (recognised as inventor of modern baseball, "father of baseball"), born in New York City
Herbert Spencer (1820-1903)
Apr 27 British philosopher (Social Statics) and sociologist, born in Derby, England
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Silent Generation
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