MLA
Robertson, John, 1787-1873. Letters on the subject of southern wrongs and remedies. 1861. Civil War Imprints. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/634sj3v1s7-cor.
APA, 6th edition
Robertson, John, 1787-1873. (1861)[Letters on the subject of southern wrongs and remedies]. Civil War Imprints, Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/634sj3v1s7-cor.
Chicago
Robertson, John, 1787-1873, Letters on the subject of southern wrongs and remedies, 1861, Civil War Imprints, Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/634sj3v1s7-cor.