MLA
Ward, A. J. Letter from A. J. Ward (Camp Lee near Richmond, Virginia) to His Brother and Sisters, Describing the Recent Battle at Fredericksburg Which He Took Part in - May 19, 1863. 1863. Stuart A. Rose Manuscript, Archives, and Rare Book Library, Box 5, Folder 14. https://digital.library.emory.edu/purl/9117m0ch07-cor.
APA, 6th edition
Ward, A. J. (1863). Letter from A. J. Ward (Camp Lee near Richmond, Virginia) to his brother and sisters, describing the recent battle at Fredericksburg which he took part in - May 19, 1863 (Box 5, Folder 14) [Letters (correspondence)]. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/9117m0ch07-cor.
Chicago
Ward, A. J. “Letter from A. J. Ward (Camp Lee near Richmond, Virginia) to His Brother and Sisters, Describing the Recent Battle at Fredericksburg Which He Took Part in - May 19, 1863.” Letters (correspondence). Civil War Collection, 1863. Box 5, Folder 14. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/9117m0ch07-cor.