MLA
Letter from [Unknown] to "My Dear Friend" - November 25, 1865 (Photocopy). 1865. Stuart A. Rose Manuscript, Archives, and Rare Book Library, Box 19, Folder 35. https://digital.library.emory.edu/purl/56341ns2xv-cor.
APA, 6th edition
Letter from [unknown] to "My Dear Friend" - November 25, 1865 (photocopy) (Box 19, Folder 35). (1865). [Letters (correspondence)]. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/56341ns2xv-cor.
Chicago
“Letter from [Unknown] to ‘My Dear Friend’ - November 25, 1865 (Photocopy).” Letters (correspondence). Civil War Collection, 1865. Box 19, Folder 35. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/56341ns2xv-cor.