MLA
Pickens, F. W. (Francis Wilkinson), 1805-1869. Letter from South Carolina Governor Francis Wilkinson Pickens [Charleston] to David Flavel Jamison, about dispensation of rifles - March 13, 1861. March 13, 1861. Civil War Collection. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/098z8w9hhh-cor.
APA, 6th edition
Pickens, F. W. (Francis Wilkinson), 1805-1869. (March 13, 1861)[Letter from South Carolina Governor Francis Wilkinson Pickens [Charleston] to David Flavel Jamison, about dispensation of rifles - March 13, 1861]. Civil War Collection, Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/098z8w9hhh-cor.
Chicago
Pickens, F. W. (Francis Wilkinson), 1805-1869, Letter from South Carolina Governor Francis Wilkinson Pickens [Charleston] to David Flavel Jamison, about dispensation of rifles - March 13, 1861, March 13, 1861, Civil War Collection, Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/098z8w9hhh-cor.