MLA
Eddy, E. C. It Am a Possum : an African American Man Holding an Opossum, in So. Pines, N.C. 1917. Stuart A. Rose Manuscript, Archives, and Rare Book Library, Box 69. https://digital.library.emory.edu/purl/3009w0vt7f-cor.
APA, 6th edition
Eddy, E. C. (1917). It am a possum : an African American man holding an opossum, in So. Pines, N.C. (Box 69) [Postcards]. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/3009w0vt7f-cor.
Chicago
Eddy, E. C. “It Am a Possum : an African American Man Holding an Opossum, in So. Pines, N.C.” Postcards. Robert Langmuir African American Photograph Collection, 1917. Box 69. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/3009w0vt7f-cor.