MLA
Legerton, C. L. Rapid Transit : African American Man in an Ox-Drawn Cart. 1900. Stuart A. Rose Manuscript, Archives, and Rare Book Library, Box 75. https://digital.library.emory.edu/purl/965v6wwq25-cor.
APA, 6th edition
Legerton, C. L. (1900). Rapid transit : African American man in an ox-drawn cart (Box 75) [Photographic postcards]. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/965v6wwq25-cor.
Chicago
Legerton, C. L. “Rapid Transit : African American Man in an Ox-Drawn Cart.” Photographic postcards. Robert Langmuir African American Photograph Collection, 1900. Box 75. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/965v6wwq25-cor.