UNC and Duke's archival collections are both available for you to use free of charge. At each library, you'll need to register to use the materials including showing at photo ID. For collections at Duke University, you'll need to request materials 48 hours in advance of your visit, since most of the materials are stored offsite.
Contact Matt Turi, Manuscripts Research and Instruction Librarian at Wilson Special Collections Library, with any questions about primary source materials. Matt's email is turi@email.unc.edu.