MLA
Guffin, James. Letter from James Guffin (Camp near Kingsport, Tennessee) to Wife, Mary J. Guffin and Children. Guffin Served in the 4th Regiment, Georgia Cavalry - January 23, 1865 (Typescript). 1865. Stuart A. Rose Manuscript, Archives, and Rare Book Library, Box 3, Folder 43. https://digital.library.emory.edu/purl/839k3j9mf4-cor.
APA, 6th edition
Guffin, J. (1865). Letter from James Guffin (camp near Kingsport, Tennessee) to wife, Mary J. Guffin and children. Guffin served in the 4th Regiment, Georgia Cavalry - January 23, 1865 (typescript) (Box 3, Folder 43) [Letters (correspondence)]. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/839k3j9mf4-cor.
Chicago
Guffin, James. “Letter from James Guffin (Camp near Kingsport, Tennessee) to Wife, Mary J. Guffin and Children. Guffin Served in the 4th Regiment, Georgia Cavalry - January 23, 1865 (Typescript).” Letters (correspondence). Civil War Collection, 1865. Box 3, Folder 43. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/839k3j9mf4-cor.