MLA
Union Patriotic Envelope with Jefferson Davis Cartoon - "J. D. His Marque, A. L. His Marks". 1861. Stuart A. Rose Manuscript, Archives, and Rare Book Library, Box 21, Folder 4. https://digital.library.emory.edu/purl/7375tb2sjp-cor.
APA, 6th edition
Union patriotic envelope with Jefferson Davis cartoon - "J. D. His Marque, A. L. His Marks" (Box 21, Folder 4). (1861). [Envelopes]. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/7375tb2sjp-cor.
Chicago
“Union Patriotic Envelope with Jefferson Davis Cartoon - ‘J. D. His Marque, A. L. His Marks.’” Envelopes. Civil War Collection, 1861. Box 21, Folder 4. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/7375tb2sjp-cor.