MLA
Peacock, D. W. K. Letter from D. W. K. Peacock (Macon, Georgia) to G. W. Garmany (Quitman, Georgia) - April 12, 1865ﾠ. 1865. Stuart A. Rose Manuscript, Archives, and Rare Book Library, Box 5, Folder 41. https://digital.library.emory.edu/purl/180vq83cj9-cor.
APA, 6th edition
Peacock, D. W. K. (1865). Letter from D. W. K. Peacock (Macon, Georgia) to G. W. Garmany (Quitman, Georgia) - April 12, 1865ﾠ (Box 5, Folder 41) [Letters (correspondence)]. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/180vq83cj9-cor.
Chicago
Peacock, D. W. K. “Letter from D. W. K. Peacock (Macon, Georgia) to G. W. Garmany (Quitman, Georgia) - April 12, 1865ﾠ.” Letters (correspondence). Civil War Collection, 1865. Box 5, Folder 41. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/180vq83cj9-cor.