MLA
Spencer, Thomas. Confederate Trenches at Pine Mountain, Georgia. Confederate General Leonidas Polk Was Killed Here. 1940. Stuart A. Rose Manuscript, Archives, and Rare Book Library, Box 15, Folder 2. https://digital.library.emory.edu/purl/573bzkh2cq-cor.
APA, 6th edition
Spencer, T. (1940). Confederate trenches at Pine Mountain, Georgia. Confederate general Leonidas Polk was killed here (Box 15, Folder 2) [Black-and-white photographs]. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/573bzkh2cq-cor.
Chicago
Spencer, Thomas. “Confederate Trenches at Pine Mountain, Georgia. Confederate General Leonidas Polk Was Killed Here.” Black-and-white photographs. Civil War Collection, 1940. Box 15, Folder 2. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/573bzkh2cq-cor.