MLA
Thayer, Frank S. Negro Characters, New Orleans : African American Woman Standing behind a Basket, an African American Woman Sitting on a Set of Steps, an African American Man Standing with a Walking Stick, and Three African Americans in Front of a House. 1915. Stuart A. Rose Manuscript, Archives, and Rare Book Library, Box 72. https://digital.library.emory.edu/purl/286nzs7h5z-cor.
APA, 6th edition
Thayer, F. S. (1915). Negro characters, New Orleans : African American woman standing behind a basket, an African American woman sitting on a set of steps, an African American man standing with a walking stick, and three African Americans in front of a house (Box 72) [Postcards]. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/286nzs7h5z-cor.
Chicago
Thayer, Frank S. “Negro Characters, New Orleans : African American Woman Standing behind a Basket, an African American Woman Sitting on a Set of Steps, an African American Man Standing with a Walking Stick, and Three African Americans in Front of a House.” Postcards. Robert Langmuir African American Photograph Collection, 1915. Box 72. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/286nzs7h5z-cor.