MLA
Anthony, E. Union General George B. McClellan. E. Anthony, 1861. Stuart A. Rose Manuscript, Archives, and Rare Book Library, Box 22, Folder 34. https://digital.library.emory.edu/purl/269m37pwv3-cor.
APA, 6th edition
Anthony, E. (1861). Union general George B. McClellan (Box 22, Folder 34) [Cartes-de-visite (card photographs)]. E. Anthony; Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/269m37pwv3-cor.
Chicago
Anthony, E. “Union General George B. McClellan.” Cartes-de-visite (card photographs). Civil War Collection. New York City, NY: E. Anthony, 1861. Box 22, Folder 34. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/269m37pwv3-cor.