MLA
Capers, William, 1790-1855. Letter from William Capers (Anderson, [South Carolina]) to Robert Paine (Aberdeen, Mississippi) - March 22, 1853. March 22, 1853. Robert Paine Papers, 1828-1882. Pitts Theology Library. https://digital.library.emory.edu/purl/1504xgxf6v-cor.
APA, 6th edition
Capers, William, 1790-1855. (March 22, 1853)[Letter from William Capers (Anderson, [South Carolina]) to Robert Paine (Aberdeen, Mississippi) - March 22, 1853]. Robert Paine Papers, 1828-1882, Pitts Theology Library. https://digital.library.emory.edu/purl/1504xgxf6v-cor.
Chicago
Capers, William, 1790-1855, Letter from William Capers (Anderson, [South Carolina]) to Robert Paine (Aberdeen, Mississippi) - March 22, 1853, March 22, 1853, Robert Paine Papers, 1828-1882, Pitts Theology Library. https://digital.library.emory.edu/purl/1504xgxf6v-cor.