MLA
Workman, Will. Letter from Will Workman (Richmond, Virginia) to "Dear Miss Jane". Workman Served in Company K of the 7th South Carolina Cavalry - October 1864 (Typescript). 1864. Stuart A. Rose Manuscript, Archives, and Rare Book Library, Box 7, Folder 42. https://digital.library.emory.edu/purl/515bcc2grp-cor.
APA, 6th edition
Workman, W. (1864). Letter from Will Workman (Richmond, Virginia) to "Dear Miss Jane". Workman served in Company K of the 7th South Carolina Cavalry - October 1864 (typescript) (Box 7, Folder 42) [Letters (correspondence)]. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/515bcc2grp-cor.
Chicago
Workman, Will. “Letter from Will Workman (Richmond, Virginia) to ‘Dear Miss Jane’. Workman Served in Company K of the 7th South Carolina Cavalry - October 1864 (Typescript).” Letters (correspondence). Civil War Collection, 1864. Box 7, Folder 42. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/515bcc2grp-cor.