MLA
Hatten, N. F. Letter from N. F. Hatten (Camp near New Market, Tennessee) to Mr. G. H. Brewer. Hatten Served in Company G of the 10th Georgia Infantry Regiment - February 15, 1864. 1864. Stuart A. Rose Manuscript, Archives, and Rare Book Library, Box 3, Folder 54. https://digital.library.emory.edu/purl/68605qfvs4-cor.
APA, 6th edition
Hatten, N. F. (1864). Letter from N. F. Hatten (camp near New Market, Tennessee) to Mr. G. H. Brewer. Hatten served in Company G of the 10th Georgia Infantry Regiment - February 15, 1864 (Box 3, Folder 54) [Letters (correspondence)]. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/68605qfvs4-cor.
Chicago
Hatten, N. F. “Letter from N. F. Hatten (Camp near New Market, Tennessee) to Mr. G. H. Brewer. Hatten Served in Company G of the 10th Georgia Infantry Regiment - February 15, 1864.” Letters (correspondence). Civil War Collection, 1864. Box 3, Folder 54. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/68605qfvs4-cor.