MLA
Leavell, George W. Letter from George W. Leavell (DeKalb County, Georgia) to "Lieutenant W. W. Crockett." Leavell Served in Company E of the 7th Georgia Infantry Regiment - January 14, 1865. 1865. Stuart A. Rose Manuscript, Archives, and Rare Book Library, Box 4, Folder 40. https://digital.library.emory.edu/purl/389280gc5j-cor.
APA, 6th edition
Leavell, G. W. (1865). Letter from George W. Leavell (DeKalb County, Georgia) to "Lieutenant W. W. Crockett." Leavell served in Company E of the 7th Georgia Infantry Regiment - January 14, 1865 (Box 4, Folder 40) [Letters (correspondence)]. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/389280gc5j-cor.
Chicago
Leavell, George W. “Letter from George W. Leavell (DeKalb County, Georgia) to ‘Lieutenant W. W. Crockett." Leavell Served in Company E of the 7th Georgia Infantry Regiment - January 14, 1865.” Letters (correspondence). Civil War Collection, 1865. Box 4, Folder 40. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/389280gc5j-cor.