MLA
Letter from Unknown Soldier at Chimborazo Hospital (Richmond, Virginia) to His Wife - March, 1865. 1865. Stuart A. Rose Manuscript, Archives, and Rare Book Library, Box 2, Folder 18. https://digital.library.emory.edu/purl/187pnvx1m6-cor.
APA, 6th edition
Letter from unknown soldier at Chimborazo Hospital (Richmond, Virginia) to his wife - March, 1865 (Box 2, Folder 18). (1865). [Letters (correspondence)]. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/187pnvx1m6-cor.
Chicago
“Letter from Unknown Soldier at Chimborazo Hospital (Richmond, Virginia) to His Wife - March, 1865.” Letters (correspondence). Civil War Collection, 1865. Box 2, Folder 18. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/187pnvx1m6-cor.