MLA
Letter from an Unknown Soldier (Lynchburg, Virginia), to His Mother and Sister - September 4, 1862. 1862. Stuart A. Rose Manuscript, Archives, and Rare Book Library, Box 6, Folder 75. https://digital.library.emory.edu/purl/2902z34v99-cor.
APA, 6th edition
Letter from an unknown soldier (Lynchburg, Virginia), to his mother and sister - September 4, 1862 (Box 6, Folder 75). (1862). [Letters (correspondence)]. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/2902z34v99-cor.
Chicago
“Letter from an Unknown Soldier (Lynchburg, Virginia), to His Mother and Sister - September 4, 1862.” Letters (correspondence). Civil War Collection, 1862. Box 6, Folder 75. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/2902z34v99-cor.