MLA
Hurd, C. D. The Old Stone House, Clinton, Iowa : This House Was a Place of Refuge for Fugitive Slaves during Slavery Days. Stuart A. Rose Manuscript, Archives, and Rare Book Library, Box 75. https://digital.library.emory.edu/purl/354xgxd279-cor.
APA, 6th edition
Hurd, C. D. The old stone house, Clinton, Iowa : this house was a place of refuge for fugitive slaves during slavery days (Box 75) [Postcards]. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/354xgxd279-cor.
Chicago
Hurd, C. D. “The Old Stone House, Clinton, Iowa : This House Was a Place of Refuge for Fugitive Slaves during Slavery Days.” Postcards. Robert Langmuir African American Photograph Collection, n.d. Box 75. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/354xgxd279-cor.