MLA
Morrow, J. M. Letter from J. M. Morrow (Camp near Warwick Courthouse, Virginia) to His Father J. H. Morrow. Morrow Probably Served in Company E of the 10th Georgia Infantry Regiment (Clayton Sharpshooters) - September 18, 1861. 1861. Stuart A. Rose Manuscript, Archives, and Rare Book Library, Box 5, Folder 31. https://digital.library.emory.edu/purl/501pg4f5sq-cor.
APA, 6th edition
Morrow, J. M. (1861). Letter from J. M. Morrow (camp near Warwick courthouse, Virginia) to his father J. H. Morrow. Morrow probably served in Company E of the 10th Georgia Infantry Regiment (Clayton Sharpshooters) - September 18, 1861 (Box 5, Folder 31) [Letters (correspondence)]. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/501pg4f5sq-cor.
Chicago
Morrow, J. M. “Letter from J. M. Morrow (Camp near Warwick Courthouse, Virginia) to His Father J. H. Morrow. Morrow Probably Served in Company E of the 10th Georgia Infantry Regiment (Clayton Sharpshooters) - September 18, 1861.” Letters (correspondence). Civil War Collection, 1861. Box 5, Folder 31. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/501pg4f5sq-cor.