MLA
Lewis, W. C. Letter from W. C. Lewis (Rural Retreat, Virginia) to Robert Paine (Aberdeen, Mississippi) - February 11, 1855. 1855. Pitts Theology Library, Box 1, Folder 13. https://digital.library.emory.edu/purl/095j9kd670-cor.
APA, 6th edition
Lewis, W. C. (1855). Letter from W. C. Lewis (Rural Retreat, Virginia) to Robert Paine (Aberdeen, Mississippi) - February 11, 1855 (Box 1, Folder 13) [Letters (correspondence)]. Pitts Theology Library. https://digital.library.emory.edu/purl/095j9kd670-cor.
Chicago
Lewis, W. C. “Letter from W. C. Lewis (Rural Retreat, Virginia) to Robert Paine (Aberdeen, Mississippi) - February 11, 1855.” Letters (correspondence). Robert Paine Papers, 1828-1882, 1855. Box 1, Folder 13. Pitts Theology Library. https://digital.library.emory.edu/purl/095j9kd670-cor.