MLA
Lindsey, J. B. Letter from J. B. Lindsey to "Dear Father and Mother" - May 25, 1862. 1862. Stuart A. Rose Manuscript, Archives, and Rare Book Library, Box 4, Folder 48. https://digital.library.emory.edu/purl/750tqjq3cm-cor.
APA, 6th edition
Lindsey, J. B. (1862). Letter from J. B. Lindsey to "Dear Father and Mother" - May 25, 1862 (Box 4, Folder 48) [Letters (correspondence)]. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/750tqjq3cm-cor.
Chicago
Lindsey, J. B. “Letter from J. B. Lindsey to ‘Dear Father and Mother’ - May 25, 1862.” Letters (correspondence). Civil War Collection, 1862. Box 4, Folder 48. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/750tqjq3cm-cor.