- Mar 6 William Claflin, 27th Governor of Massachusetts (d. 1905)
- Mar 10 George Wythe Randolph, American Secretary of War for the Confederacy, born in Charlottesville, Virginia (d. 1867)
- Mar 11 John Wilkins Whitfield, American Brigadier General (Confederate Army), born in Franklin, Tennessee (d. 1879)
- Mar 12 John Lorimar Worden, Capt (Union Navy), (d. 1897)
- Mar 13 Albion Parris Howe, American Brevet Major General (Union Army), born in Standish, Maine (d. 1897)
- Mar 15 Mariano Álvarez, Filipino general (d. 1924)
- Mar 22 John Ainsworth Horrocks, English-born explorer of South Australia (d. 1846)
- Mar 23 Don Carlos Buell, American Major General (Union Army), born in Lowell, Ohio (d. 1898)
- Mar 25 Isaac Ingalls Stevens, American Major General (Union Army), born in North Andover, Massachusetts (d. 1862)
- Mar 27 Jacob Axel Josephson, Swedish composer, born in Stockholm, Sweden (d. 1880)
- Mar 28 Wade Hampton, American politician, Lt Gen (Confederate Army), born in Charleston, South Carolina (d. 1902)