- Apr 3 Edward Everett Hale, American clergyman and author (Man without a Country), born in Boston, Massachusetts (d. 1909)
- Apr 5 James Nagle, American Brigadier General (Union Army), born in Reading, Pennsylvania (d. 1866)
- Apr 7 Gershom Mott, American Major General (Union Army), born in Lamberton, New Jersey (d. 1884)
- Apr 13 Leroy Augustus Stafford, American Brigadier General (Confederate Army), born in Cheneyville Rapides Parish, Louisiana (d. 1864)
- Apr 13 William Stephen Walker, American Brigadier General (Confederate Army), born in Pittsburgh, Pennsylvania (d. 1899)
- Apr 15 Napoleon Jackson Tecumseh Dana, American Major General (Union Army), born in Eastport, Maine (d. 1905)
- Apr 21 Hannibal Goodwin, Episcopal priest who patented a method for making film used in Thomas Edison's Kinetoscope, born in Taughannock, New York (d. 1900)
- Apr 24 Erastus Barnard Tyler, American businessman, merchant, and Brevet Major General (Union Army), born in West Bloomfield, New York (d. 1891)
Frederick Law Olmsted (1822-1903)
Apr 26 American writer and landscape architect (designed Central Park), born in Hartford, Connecticut
- Apr 26 Jan Albert van Eijken, Dutch composer and organist, born in Amersfoort, Netherlands (d. 1868)
Ulysses S. Grant (1822-1885)
Apr 27 18th US President (1869-77) and Union general, born in Point Pleasant, Ohio
