MLA
Echols, James Jewell. Letter from James Jewell Echols (Atlanta, Georgia) to "Dear Sister," Describing the Escape of 12 Prisoners and the Efforts Made to Recapture Them - October 19, 1862 (Photocopy). 1862. Stuart A. Rose Manuscript, Archives, and Rare Book Library, Box 3, Folder 15. https://digital.library.emory.edu/purl/286nzs7j4c-cor.
APA, 6th edition
Echols, J. J. (1862). Letter from James Jewell Echols (Atlanta, Georgia) to "Dear Sister," describing the escape of 12 prisoners and the efforts made to recapture them - October 19, 1862 (photocopy) (Box 3, Folder 15) [Letters (correspondence)]. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/286nzs7j4c-cor.
Chicago
Echols, James Jewell. “Letter from James Jewell Echols (Atlanta, Georgia) to ‘Dear Sister," Describing the Escape of 12 Prisoners and the Efforts Made to Recapture Them - October 19, 1862 (Photocopy).” Letters (correspondence). Civil War Collection, 1862. Box 3, Folder 15. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/286nzs7j4c-cor.