MLA
Hoskins, John S. Letter from John S. Hoskins to His Wife. He Served as a Captain in the 38th Mississippi Infantry Regiment - November 2, 1863 (Photocopy). 1863. Stuart A. Rose Manuscript, Archives, and Rare Book Library, Box 3, Folder 63. https://digital.library.emory.edu/purl/873pvmcwg2-cor.
APA, 6th edition
Hoskins, J. S. (1863). Letter from John S. Hoskins to his wife. He served as a captain in the 38th Mississippi Infantry Regiment - November 2, 1863 (photocopy) (Box 3, Folder 63) [Letters (correspondence)]. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/873pvmcwg2-cor.
Chicago
Hoskins, John S. “Letter from John S. Hoskins to His Wife. He Served as a Captain in the 38th Mississippi Infantry Regiment - November 2, 1863 (Photocopy).” Letters (correspondence). Civil War Collection, 1863. Box 3, Folder 63. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/873pvmcwg2-cor.