MLA
Russell, J. P. Letter from J. P. Russell (Camp near Canton [Mississippi?]) to "Miss Fannie" - November 4, 1863. 1863. Stuart A. Rose Manuscript, Archives, and Rare Book Library, Box 6, Folder 8. https://digital.library.emory.edu/purl/293gxd25sm-cor.
APA, 6th edition
Russell, J. P. (1863). Letter from J. P. Russell (camp near Canton [Mississippi?]) to "Miss Fannie" - November 4, 1863 (Box 6, Folder 8) [Letters (correspondence)]. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/293gxd25sm-cor.
Chicago
Russell, J. P. “Letter from J. P. Russell (Camp near Canton [Mississippi?]) to ‘Miss Fannie’ - November 4, 1863.” Letters (correspondence). Civil War Collection, 1863. Box 6, Folder 8. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/293gxd25sm-cor.