MLA
Reep, Rueben Beale. Fragment of a Letter from Reuben Beale Reep (Murfreesboro, Tennessee). Reep Was a Member of the 105th Ohio Infantry Regiment, Company A, and Entered Service on August 1862 and Died in a Field Hospita in, Cowan, Tennessee on July or August, 1863. 1862. Stuart A. Rose Manuscript, Archives, and Rare Book Library, Box 20, Folder 17. https://digital.library.emory.edu/purl/3311ns1sqb-cor.
APA, 6th edition
Reep, R. B. (1862). Fragment of a letter from Reuben Beale Reep (Murfreesboro, Tennessee). Reep was a member of the 105th Ohio Infantry Regiment, Company A, and entered service on August 1862 and died in a field hospita in, Cowan, Tennessee on July or August, 1863 (Box 20, Folder 17) [Letters (correspondence)]. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/3311ns1sqb-cor.
Chicago
Reep, Rueben Beale. “Fragment of a Letter from Reuben Beale Reep (Murfreesboro, Tennessee). Reep Was a Member of the 105th Ohio Infantry Regiment, Company A, and Entered Service on August 1862 and Died in a Field Hospita in, Cowan, Tennessee on July or August, 1863.” Letters (correspondence). Civil War Collection, 1862. Box 20, Folder 17. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/3311ns1sqb-cor.