MLA
Envelope Addressed to an Unidentified Individual. 1863. Stuart A. Rose Manuscript, Archives, and Rare Book Library, Box 6, Folder 53. https://digital.library.emory.edu/purl/303qv9s59v-cor.
APA, 6th edition
Envelope addressed to an unidentified individual (Box 6, Folder 53). (1863). [Envelopes]. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/303qv9s59v-cor.
Chicago
“Envelope Addressed to an Unidentified Individual.” Envelopes. Civil War Collection, 1863. Box 6, Folder 53. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/303qv9s59v-cor.