MLA
Union Patriotic Envelope with George Washington Cartoon. 1861. Stuart A. Rose Manuscript, Archives, and Rare Book Library, Box 21, Folder 6. https://digital.library.emory.edu/purl/682k6djjkf-cor.
APA, 6th edition
Union patriotic envelope with George Washington cartoon (Box 21, Folder 6). (1861). [Envelopes]. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/682k6djjkf-cor.
Chicago
“Union Patriotic Envelope with George Washington Cartoon.” Envelopes. Civil War Collection, 1861. Box 21, Folder 6. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/682k6djjkf-cor.