MLA
Thomas, John. Letter by John Thomas to Captain George M. Hanvey; Hanvey Served in the 1st Georgia Infantry Regiment (Ramsey's); Later Company A of the 12th Battalion Georgia Light Artillery - May 7, 1861 (Photocopy). 1861. Stuart A. Rose Manuscript, Archives, and Rare Book Library, Box 3, Folder. https://digital.library.emory.edu/purl/24947d7xmt-cor.
APA, 6th edition
Thomas, J. (1861). Letter by John Thomas to Captain George M. Hanvey; Hanvey served in the 1st Georgia Infantry Regiment (Ramsey's); later Company A of the 12th Battalion Georgia Light Artillery - May 7, 1861 (photocopy) (Box 3, Folder) [Letters (correspondence)]. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/24947d7xmt-cor.
Chicago
Thomas, John. “Letter by John Thomas to Captain George M. Hanvey; Hanvey Served in the 1st Georgia Infantry Regiment (Ramsey's); Later Company A of the 12th Battalion Georgia Light Artillery - May 7, 1861 (Photocopy).” Letters (correspondence). Civil War Collection, 1861. Box 3, Folder. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/24947d7xmt-cor.