MLA
Edmonds, William M. Letter from William M. Edmonds to His Sister, Mrs. Margaret Preston. Edmonds Served in the 9th Arkansas Infantry Regiment - December 9, 1861. 1861. Stuart A. Rose Manuscript, Archives, and Rare Book Library, Box 3, Folder 17. https://digital.library.emory.edu/purl/873pvmcwg0-cor.
APA, 6th edition
Edmonds, W. M. (1861). Letter from William M. Edmonds to his sister, Mrs. Margaret Preston. Edmonds served in the 9th Arkansas Infantry Regiment - December 9, 1861 (Box 3, Folder 17) [Letters (correspondence)]. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/873pvmcwg0-cor.
Chicago
Edmonds, William M. “Letter from William M. Edmonds to His Sister, Mrs. Margaret Preston. Edmonds Served in the 9th Arkansas Infantry Regiment - December 9, 1861.” Letters (correspondence). Civil War Collection, 1861. Box 3, Folder 17. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/873pvmcwg0-cor.