MLA
Joseph Horne Co.'s Final Delivery Man and Their Oldest Employee, Robert, in Pittsburgh in 1866. Stuart A. Rose Manuscript, Archives, and Rare Book Library, Box 29. https://digital.library.emory.edu/purl/822h70rz18-cor.
APA, 6th edition
Joseph Horne Co.'s final delivery man and their oldest employee, Robert, in Pittsburgh in 1866 (Box 29). [Black-and-white photographs]. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/822h70rz18-cor.
Chicago
“Joseph Horne Co.'s Final Delivery Man and Their Oldest Employee, Robert, in Pittsburgh in 1866.” Black-and-white photographs. Robert Langmuir African American Photograph Collection, n.d. Box 29. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/822h70rz18-cor.