Collection
- Campbell family papers, 1860-1865, 1879-19491
- Carl M. Weideman Papers, 1921-1972 (majority within 1932-1934)1
- Carl Rominger family papers, 1840-19451
- Carlisle Family papers, 1860-19721
- Carlton F. Wells papers, 1910-19941
- Cavanagh Family papers, 1857-20061
- Charles A. Simpson papers, 1910-19321
- Charles A. Sink Papers, 1900-19961
- Charles B. Haydon Papers, 1852-1864 (majority within 1861-1864)1
- Charles Brady Ryan papers, 1916-19191
- Charles David Williams papers, 1878-19231
- Charles Horace Hodskin diary, 18641
- Charles Horton Cooley papers, 1872-19301
- Charles L. Follo papers, 1961-19701
- Charles L. Stevenson papers, 1841-1846, 1925-19791
- Chase S. Osborn Papers, circa 1870-1949 (majority within 1889-1949)1
- Chester M. Howell papers, circa 1910-1990 (majority within 1950-1980)1
- Christina V. Pacosz papers, 1899-2019 (majority within 1961-2012)1
- Clara H. Brucker papers, 1920-19801
- Clara Hadley Wait papers, 1893-2001 (majority within 1893-1919)1