MLA
Day of Execution of John Brown, Charlestown, W. Va., Dec. 2nd, 1859. Stuart A. Rose Manuscript, Archives, and Rare Book Library, Box 69. https://digital.library.emory.edu/purl/56341ns1vd-cor.
APA, 6th edition
Day of execution of John Brown, Charlestown, W. Va., Dec. 2nd, 1859 (Box 69). [Postcards]. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/56341ns1vd-cor.
Chicago
“Day of Execution of John Brown, Charlestown, W. Va., Dec. 2nd, 1859.” Postcards. Robert Langmuir African American Photograph Collection, n.d. Box 69. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/56341ns1vd-cor.