MLA
Scott, James M. Letter Written by James M. Scott to His Wife, Liz. Scott Was a Captain in the 80th Ohio Regiment - April 17, 1865 (Photocopy). 1865. Stuart A. Rose Manuscript, Archives, and Rare Book Library, Box 20, Folder 20. https://digital.library.emory.edu/purl/204rjdfp74-cor.
APA, 6th edition
Scott, J. M. (1865). Letter written by James M. Scott to his wife, Liz. Scott was a captain in the 80th Ohio Regiment - April 17, 1865 (photocopy) (Box 20, Folder 20) [Letters (correspondence)]. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/204rjdfp74-cor.
Chicago
Scott, James M. “Letter Written by James M. Scott to His Wife, Liz. Scott Was a Captain in the 80th Ohio Regiment - April 17, 1865 (Photocopy).” Letters (correspondence). Civil War Collection, 1865. Box 20, Folder 20. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/204rjdfp74-cor.