MLA
Capers, William, 1790-1855, Paine, Robert, 1799-1882. Letter from William Capers (Charleston, South Carolina) to Robert Paine (Fayette County, Tennessee) - March 13, 1848. March 13, 1848. Robert Paine Papers, 1828-1882. Pitts Theology Library. https://digital.library.emory.edu/purl/788cfxpq2z-cor.
APA, 6th edition
Capers, William, 1790-1855, & Paine, Robert, 1799-1882. (March 13, 1848)[Letter from William Capers (Charleston, South Carolina) to Robert Paine (Fayette County, Tennessee) - March 13, 1848]. Robert Paine Papers, 1828-1882, Pitts Theology Library. https://digital.library.emory.edu/purl/788cfxpq2z-cor.
Chicago
Capers, William, 1790-1855, Paine, Robert, 1799-1882, Letter from William Capers (Charleston, South Carolina) to Robert Paine (Fayette County, Tennessee) - March 13, 1848, March 13, 1848, Robert Paine Papers, 1828-1882, Pitts Theology Library. https://digital.library.emory.edu/purl/788cfxpq2z-cor.