MLA
Lasco, John G. Letter from John G. Lasco (Savannah, Georgia) to General William E. Mickle - March 15, 1874. 1874. Stuart A. Rose Manuscript, Archives, and Rare Book Library, Box 9, Folder 6. https://digital.library.emory.edu/purl/201bk3jbp4-cor.
APA, 6th edition
Lasco, J. G. (1874). Letter from John G. Lasco (Savannah, Georgia) to General William E. Mickle - March 15, 1874 (Box 9, Folder 6) [Letters (correspondence)]. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/201bk3jbp4-cor.
Chicago
Lasco, John G. “Letter from John G. Lasco (Savannah, Georgia) to General William E. Mickle - March 15, 1874.” Letters (correspondence). Civil War Collection, 1874. Box 9, Folder 6. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/201bk3jbp4-cor.