MLA
Letter from an Unknown Civilian (Charlotte, North Carolina) to ???Dear Auntie??? - August 19, 1864. 1864. Stuart A. Rose Manuscript, Archives, and Rare Book Library, Box 6, Folder 62. https://digital.library.emory.edu/purl/706g1jwtht-cor.
APA, 6th edition
Letter from an unknown civilian (Charlotte, North Carolina) to ???Dear Auntie??? - August 19, 1864 (Box 6, Folder 62). (1864). [Letters (correspondence)]. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/706g1jwtht-cor.
Chicago
“Letter from an Unknown Civilian (Charlotte, North Carolina) to ???Dear Auntie??? - August 19, 1864.” Letters (correspondence). Civil War Collection, 1864. Box 6, Folder 62. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/706g1jwtht-cor.