- Churches of Somerset County, Pennsylvania, Records, 1775/19331
- Clarence Edwin Smith (1885-1959) Papers, 1787/19572
- Clarence Edwin Smith (1885-1959), Barns Family Papers, 1795/19081
- Clarksburg Public Library, Collector, Miscellaneous Papers, 1782/18651
- Cleaver Family Papers, 1777/19691
- Collection of the Hulver Family and Baughman Settlement, Hardy County, West Virginia, 1800/2013, bulk 1830/19501
- Currency Collection, 1772/18991
- D. Boston Stewart Papers, 1782/1919, bulk 1862/19061
- David Hunter Strother, Artist, Artwork and Papers, 1744/1996, bulk 1833/18877
- David Merle Shingleton, Jr., Author, Shingleton Family Genealogy, 2010/20111
- Davis Family Papers, 1800/19411
- Davis-Meranda Family of Clark County, Ohio, Genealogy, 1770/18501
- Deakins Family Papers and Surveying Compass, 1778/19251
- Deakins Family Papers, 1778/19251
- Dille Family of Monongalia County (W.Va.), Financial, Legal, and Military Papers, 1785/1896, bulk 1816/18751