Collection
- Calvin Thomas Papers, 1838-1940 (majority within 1872-1919)1
- Camp of the 16th Michigan Regiment near Fredericksburg [graphic], 18621
- Campbell family papers, 1860-1865, 1879-19491
- Carlisle Family papers, 1860-19721
- Carr family papers, 1861-19301
- Charles Adam Weissert papers, 1893-19471
- Charles B. Haydon Papers, 1852-1864 (majority within 1861-1864)1
- Charles Butler correspondence, 1862-18641
- Charles F. Bates papers, 1861-18881
- Charles Horace Hodskin diary, 18641
- Charles Oscar Adams letters, 1861-18621
- Chase S. Osborn Papers, circa 1870-1949 (majority within 1889-1949)1
- Civil War Portrait Collection, circa 1861-18651
- Clark E. Mills diary, 18651
- Claudius Buchanan Grant papers, 1830s-19241
- Conant Family papers, 1833-20011
- Daniel J. Cobb letters, 1862-18651
- David Walbridge Kendall papers, 1862-1865, 1891-1924, 1932-1976 (majority within 1932-1971)1
- Davis family (Grand Rapids and Pontiac, Mich.) papers, 1796-18911
- De Witt C. Spaulding papers, 1861-1926 (scattered), 2011 (majority within 1861-1865)1