MLA
Shuler, Harrison A. Letter from Harrison A. Shuler (Camp near Richmond, Virginia) to "My Dearest Father". Harrison A. Shuler Served in Company D of the 3rd South Carolina Battalion - August 21, 1862. 1862. Stuart A. Rose Manuscript, Archives, and Rare Book Library, Box 6, Folder 21. https://digital.library.emory.edu/purl/7032280h0b-cor.
APA, 6th edition
Shuler, H. A. (1862). Letter from Harrison A. Shuler (Camp near Richmond, Virginia) to "My Dearest Father". Harrison A. Shuler served in Company D of the 3rd South Carolina Battalion - August 21, 1862 (Box 6, Folder 21) [Letters (correspondence)]. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/7032280h0b-cor.
Chicago
Shuler, Harrison A. “Letter from Harrison A. Shuler (Camp near Richmond, Virginia) to ‘My Dearest Father’. Harrison A. Shuler Served in Company D of the 3rd South Carolina Battalion - August 21, 1862.” Letters (correspondence). Civil War Collection, 1862. Box 6, Folder 21. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/7032280h0b-cor.