MLA
Spencer, Thomas. Tombstone of Russel Gregory in Gatlinburg, Tennessee. Gregory Was pro-Union Inhabitant of Cades Cove, Tennessee, and Was Killed by North Carolina Confederates Troops in 1864. 1961. Stuart A. Rose Manuscript, Archives, and Rare Book Library, Box 15, Folder 7. https://digital.library.emory.edu/purl/24947d7xrg-cor.
APA, 6th edition
Spencer, T. (1961). Tombstone of Russel Gregory in Gatlinburg, Tennessee. Gregory was pro-Union inhabitant of Cades Cove, Tennessee, and was killed by North Carolina Confederates troops in 1864 (Box 15, Folder 7) [Black-and-white photographs]. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/24947d7xrg-cor.
Chicago
Spencer, Thomas. “Tombstone of Russel Gregory in Gatlinburg, Tennessee. Gregory Was pro-Union Inhabitant of Cades Cove, Tennessee, and Was Killed by North Carolina Confederates Troops in 1864.” Black-and-white photographs. Civil War Collection, 1961. Box 15, Folder 7. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/24947d7xrg-cor.