MLA
Mobley, James M. Letter from James M. Mobley (Milledgeville, Georgia) to John W. Park (Greenville, Georgia) Stating That General Wagner Had Not Received a Reply from the Governor of Georgia, and That When He Does, Park Will Be Notified - April 28, 1864. 1864. Stuart A. Rose Manuscript, Archives, and Rare Book Library, Box 5, Folder 23. https://digital.library.emory.edu/purl/204rjdfp3g-cor.
APA, 6th edition
Mobley, J. M. (1864). Letter from James M. Mobley (Milledgeville, Georgia) to John W. Park (Greenville, Georgia) stating that General Wagner had not received a reply from the Governor of Georgia, and that when he does, Park will be notified - April 28, 1864 (Box 5, Folder 23) [Letters (correspondence)]. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/204rjdfp3g-cor.
Chicago
Mobley, James M. “Letter from James M. Mobley (Milledgeville, Georgia) to John W. Park (Greenville, Georgia) Stating That General Wagner Had Not Received a Reply from the Governor of Georgia, and That When He Does, Park Will Be Notified - April 28, 1864.” Letters (correspondence). Civil War Collection, 1864. Box 5, Folder 23. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/204rjdfp3g-cor.