MLA
Richards, Rodolphe R. Letter from Rodolpe R. Richards (Tybee Island, Georgia) to His Mother (Savannah, Georgia) - October 23, 1863. 1861. Stuart A. Rose Manuscript, Archives, and Rare Book Library, Box 5, Folder 62. https://digital.library.emory.edu/purl/7375tb2sfh-cor.
APA, 6th edition
Richards, R. R. (1861). Letter from Rodolpe R. Richards (Tybee Island, Georgia) to his mother (Savannah, Georgia) - October 23, 1863 (Box 5, Folder 62) [Letters (correspondence)]. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/7375tb2sfh-cor.
Chicago
Richards, Rodolphe R. “Letter from Rodolpe R. Richards (Tybee Island, Georgia) to His Mother (Savannah, Georgia) - October 23, 1863.” Letters (correspondence). Civil War Collection, 1861. Box 5, Folder 62. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/7375tb2sfh-cor.