MLA
Jenkins, S. W. Letter from S. W. Jenkins to Susan A. Kenny. Jenkins Served in the 9th and Later the 58th Alabama Infantry Regiment - June 12, 1863. 1863. Stuart A. Rose Manuscript, Archives, and Rare Book Library, Box 4, Folder 28. https://digital.library.emory.edu/purl/2085hqc0nb-cor.
APA, 6th edition
Jenkins, S. W. (1863). Letter from S. W. Jenkins to Susan A. Kenny. Jenkins served in the 9th and later the 58th Alabama Infantry Regiment - June 12, 1863 (Box 4, Folder 28) [Letters (correspondence)]. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/2085hqc0nb-cor.
Chicago
Jenkins, S. W. “Letter from S. W. Jenkins to Susan A. Kenny. Jenkins Served in the 9th and Later the 58th Alabama Infantry Regiment - June 12, 1863.” Letters (correspondence). Civil War Collection, 1863. Box 4, Folder 28. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/2085hqc0nb-cor.