MLA
Union Patriotic Envelope with Winfield Scott Cartoon - "True to the Flag". 1861. Stuart A. Rose Manuscript, Archives, and Rare Book Library, Box 21, Folder 6. https://digital.library.emory.edu/purl/163stqjr70-cor.
APA, 6th edition
Union patriotic envelope with Winfield Scott cartoon - "True to the Flag" (Box 21, Folder 6). (1861). [Envelopes]. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/163stqjr70-cor.
Chicago
“Union Patriotic Envelope with Winfield Scott Cartoon - ‘True to the Flag.’” Envelopes. Civil War Collection, 1861. Box 21, Folder 6. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/163stqjr70-cor.