MLA
Grice, Wily. Letter from Willy Grice (Vicksburg, Mississippi) to W. F. Early - March 26, 1863. 1863. Stuart A. Rose Manuscript, Archives, and Rare Book Library, Box 3, Folder 14. https://digital.library.emory.edu/purl/7203xsj4wh-cor.
APA, 6th edition
Grice, W. (1863). Letter from Willy Grice (Vicksburg, Mississippi) to W. F. Early - March 26, 1863 (Box 3, Folder 14) [Letters (correspondence)]. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/7203xsj4wh-cor.
Chicago
Grice, Wily. “Letter from Willy Grice (Vicksburg, Mississippi) to W. F. Early - March 26, 1863.” Letters (correspondence). Civil War Collection, 1863. Box 3, Folder 14. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/7203xsj4wh-cor.