MLA
Union Patriotic Envelopes - "A Polite Invitation.". 1861. Stuart A. Rose Manuscript, Archives, and Rare Book Library, Box 21, Folder 9. https://digital.library.emory.edu/purl/38279cnq8s-cor.
APA, 6th edition
Union patriotic envelopes - "A Polite Invitation." (Box 21, Folder 9). (1861). [Envelopes]. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/38279cnq8s-cor.
Chicago
“Union Patriotic Envelopes - ‘A Polite Invitation.".” Envelopes. Civil War Collection, 1861. Box 21, Folder 9. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/38279cnq8s-cor.