MLA
Galleries, Brady's National Photographic Portrait. United States Postmaster-General and Politician Montgomery Blair. Brady's National Photographic Portrait Galleries, 1861. Stuart A. Rose Manuscript, Archives, and Rare Book Library, Box 22, Folder 4. https://digital.library.emory.edu/purl/569z08kqxz-cor.
APA, 6th edition
Galleries, B. N. P. P. (1861). United States Postmaster-General and politician Montgomery Blair (Box 22, Folder 4) [Cartes-de-visite (card photographs)]. Brady's National Photographic Portrait Galleries; Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/569z08kqxz-cor.
Chicago
Galleries, Brady's National Photographic Portrait. “United States Postmaster-General and Politician Montgomery Blair.” Cartes-de-visite (card photographs). Civil War Collection. New York City, NY: Brady's National Photographic Portrait Galleries, 1861. Box 22, Folder 4. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/569z08kqxz-cor.