MLA
Statham, Ida. Letter from Ida Statham to a "Mrs. Conyers". 1861. Stuart A. Rose Manuscript, Archives, and Rare Book Library, Box 6, Folder 33. https://digital.library.emory.edu/purl/7375tb2s30-cor.
APA, 6th edition
Statham, I. (1861). Letter from Ida Statham to a "Mrs. Conyers" (Box 6, Folder 33) [Letters (correspondence)]. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/7375tb2s30-cor.
Chicago
Statham, Ida. “Letter from Ida Statham to a ‘Mrs. Conyers.’” Letters (correspondence). Civil War Collection, 1861. Box 6, Folder 33. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/7375tb2s30-cor.