MLA
Boring, Jesse. Letter from Jesse Boring (Athens, Georgia) to Robert Paine - December 12, 1849. 1849. Pitts Theology Library, Box 1, Folder 4. https://digital.library.emory.edu/purl/959189333s-cor.
APA, 6th edition
Boring, J. (1849). Letter from Jesse Boring (Athens, Georgia) to Robert Paine - December 12, 1849 (Box 1, Folder 4) [Letters (correspondence)]. Pitts Theology Library. https://digital.library.emory.edu/purl/959189333s-cor.
Chicago
Boring, Jesse. “Letter from Jesse Boring (Athens, Georgia) to Robert Paine - December 12, 1849.” Letters (correspondence). Robert Paine Papers, 1828-1882, 1849. Box 1, Folder 4. Pitts Theology Library. https://digital.library.emory.edu/purl/959189333s-cor.