MLA
Discharge for Joshua M. Mitchell from the Union Military Prison on Johnson's Island, Ohio - January 17, 1865. 1865. Stuart A. Rose Manuscript, Archives, and Rare Book Library, Box 5, Folder 20. https://digital.library.emory.edu/purl/583kwh71sn-cor.
APA, 6th edition
Discharge for Joshua M. Mitchell from the Union military prison on Johnson's Island, Ohio - January 17, 1865 (Box 5, Folder 20). (1865). [Military records]. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/583kwh71sn-cor.
Chicago
“Discharge for Joshua M. Mitchell from the Union Military Prison on Johnson's Island, Ohio - January 17, 1865.” Military records. Civil War Collection, 1865. Box 5, Folder 20. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/583kwh71sn-cor.