MLA
Godfrey, Ervin. Letter from Ervin Godrey (Savannah, Georgia) to His Sister, Miss Hallow (Mollie) - September 24, 1859. 1859. Stuart A. Rose Manuscript, Archives, and Rare Book Library, Box 3, Folder 37. https://digital.library.emory.edu/purl/733rv15fw2-cor.
APA, 6th edition
Godfrey, E. (1859). Letter from Ervin Godrey (Savannah, Georgia) to his sister, Miss Hallow (Mollie) - September 24, 1859 (Box 3, Folder 37) [Letters (correspondence)]. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/733rv15fw2-cor.
Chicago
Godfrey, Ervin. “Letter from Ervin Godrey (Savannah, Georgia) to His Sister, Miss Hallow (Mollie) - September 24, 1859.” Letters (correspondence). Civil War Collection, 1859. Box 3, Folder 37. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/733rv15fw2-cor.