MLA
Blunt, John. Letter from John Blunt (War Station, Virginia) to "Dear Wife and Little Child" - May 19, 1863. 1863. Stuart A. Rose Manuscript, Archives, and Rare Book Library, Box 1, Folder 33. https://digital.library.emory.edu/purl/156zw3r33f-cor.
APA, 6th edition
Blunt, J. (1863). Letter from John Blunt (War Station, Virginia) to "Dear wife and little child" - May 19, 1863 (Box 1, Folder 33) [Letters (correspondence)]. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/156zw3r33f-cor.
Chicago
Blunt, John. “Letter from John Blunt (War Station, Virginia) to ‘Dear Wife and Little Child’ - May 19, 1863.” Letters (correspondence). Civil War Collection, 1863. Box 1, Folder 33. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/156zw3r33f-cor.