MLA
Mitchem, Eugene E. Letter from Eugene E. Mitchem (Point Lookout, Maryland) to His Wife, Fannie. ﾠMitchem Served in the 7th Georgia Cavalry and Was Captured at Louisa Courthouse, Virginia on June 21, 1864 - July 3, 1864 (Photocopy). 1864. Stuart A. Rose Manuscript, Archives, and Rare Book Library, Box 5, Folder 20. https://digital.library.emory.edu/purl/846d2548jp-cor.
APA, 6th edition
Mitchem, E. E. (1864). Letter from Eugene E. Mitchem (Point Lookout, Maryland) to his wife, Fannie. ﾠMitchem served in the 7th Georgia Cavalry and was captured at Louisa Courthouse, Virginia on June 21, 1864 - July 3, 1864 (photocopy) (Box 5, Folder 20) [Letters (correspondence)]. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/846d2548jp-cor.
Chicago
Mitchem, Eugene E. “Letter from Eugene E. Mitchem (Point Lookout, Maryland) to His Wife, Fannie. ﾠMitchem Served in the 7th Georgia Cavalry and Was Captured at Louisa Courthouse, Virginia on June 21, 1864 - July 3, 1864 (Photocopy).” Letters (correspondence). Civil War Collection, 1864. Box 5, Folder 20. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/846d2548jp-cor.