MLA
Enecks, W. R. Note from W. R. Enecks to Kate. 1861. Stuart A. Rose Manuscript, Archives, and Rare Book Library, Box 3, Folder 20. https://digital.library.emory.edu/purl/996k0p2pht-cor.
APA, 6th edition
Enecks, W. R. (1861). Note from W. R. Enecks to Kate (Box 3, Folder 20) [Letters (correspondence)]. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/996k0p2pht-cor.
Chicago
Enecks, W. R. “Note from W. R. Enecks to Kate.” Letters (correspondence). Civil War Collection, 1861. Box 3, Folder 20. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/996k0p2pht-cor.