MLA
Godwin, Niel. Letter from Niel Godwin (Wartrace, Tennessee) to Mary Keahey (Skippersville, Alabama). Niel Godwin Was a Lieutenant in the 33rd Alabama Infantry Regiment - June 6, 1863 (Typescript). 1863. Stuart A. Rose Manuscript, Archives, and Rare Book Library, Box 4, Folder 24. https://digital.library.emory.edu/purl/146qz613kf-cor.
APA, 6th edition
Godwin, N. (1863). Letter from Niel Godwin (Wartrace, Tennessee) to Mary Keahey (Skippersville, Alabama). Niel Godwin was a lieutenant in the 33rd Alabama Infantry Regiment - June 6, 1863 (typescript) (Box 4, Folder 24) [Letters (correspondence)]. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/146qz613kf-cor.
Chicago
Godwin, Niel. “Letter from Niel Godwin (Wartrace, Tennessee) to Mary Keahey (Skippersville, Alabama). Niel Godwin Was a Lieutenant in the 33rd Alabama Infantry Regiment - June 6, 1863 (Typescript).” Letters (correspondence). Civil War Collection, 1863. Box 4, Folder 24. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/146qz613kf-cor.