Collection
- Charlotte Pettibone Winslow papers, 1834-1910 (majority within 1834-1851)1
- Chesnut-Ewalt papers, 1834-1913 (majority within 1862-1913)1
- Childe family papers, 1733-19081
- Christopher Hughes papers, 1801-1908 (majority within 1814-1884)1
- Christopher Van Deventer papers, 1799-19251
- Clara Ballou papers, 1900-1903 (majority within 1902-1903)1
- Clark-McCreary papers, 1815-1936 (majority within 1846-1919)1
- Clarke family papers, 1823-1929 (majority within 1851-1912)1
- Clements R. Markham papers, 1859-1910 (majority within 1859-1870)1
- Clinton-Genêt family collection, 1781-19081
- Cole family papers, 1799-1959 (majority within 1821-1931)1
- Constantin Richard Schaefer papers, 1881-19111
- Continental, Confederation, and United States Congress collection, 1751-1902 (majority within 1761-1862)1
- Cornelia Hancock papers, 1862-1937 (majority within 1862-1865)1
- Cornelison papers, 1796-1929 (majority within 1887-1895)1
- Crittenden family papers, 1837-1907 (majority within 1849-1889)1
- Cummings-Durant family collection, 1844-19141
- Cushing family collection, 1790-1934 (majority within 1828-1928)1
- Dall family papers, 1824-1911, 1942 (majority within 1824-1911)1
- Daniel D. Emmett collection, 1859-19081