MLA
Hilton, Joseph. Letter from Joseph Hilton to His Cousin, Miss Lizzie Lachlison - May 15, 1863 (Typescript). 1863. Stuart A. Rose Manuscript, Archives, and Rare Book Library, Box 3, Folder 59. https://digital.library.emory.edu/purl/6042rbp0tc-cor.
APA, 6th edition
Hilton, J. (1863). Letter from Joseph Hilton to his cousin, Miss Lizzie Lachlison - May 15, 1863 (typescript) (Box 3, Folder 59) [Letters (correspondence)]. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/6042rbp0tc-cor.
Chicago
Hilton, Joseph. “Letter from Joseph Hilton to His Cousin, Miss Lizzie Lachlison - May 15, 1863 (Typescript).” Letters (correspondence). Civil War Collection, 1863. Box 3, Folder 59. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/6042rbp0tc-cor.