MLA
Smedes, W. C. (William C.). Letter of W.C. Smedes, Esq., Vicksburg, Miss., invindication of the Southern Confederacy.. 1861. Civil War Imprints. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/781jh9w41g-cor.
APA, 6th edition
Smedes, W. C. (William C.). (1861)[Letter of W.C. Smedes, Esq., Vicksburg, Miss., invindication of the Southern Confederacy.]. Civil War Imprints, Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/781jh9w41g-cor.
Chicago
Smedes, W. C. (William C.), Letter of W.C. Smedes, Esq., Vicksburg, Miss., invindication of the Southern Confederacy., 1861, Civil War Imprints, Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/781jh9w41g-cor.