MLA
Bundy, G. M. Letter from G. M. Bundy (Camp near Fredericksburg, Virginia) to His Family Detailing the Battle of Chancellorsville - May 15, 1863 [Photograph]. 1863. Stuart A. Rose Manuscript, Archives, and Rare Book Library, Box 1, Folder 42. https://digital.library.emory.edu/purl/679573n6wk-cor.
APA, 6th edition
Bundy, G. M. (1863). Letter from G. M. Bundy (camp near Fredericksburg, Virginia) to his family detailing the Battle of Chancellorsville - May 15, 1863 [photograph] (Box 1, Folder 42) [Letters (correspondence)]. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/679573n6wk-cor.
Chicago
Bundy, G. M. “Letter from G. M. Bundy (Camp near Fredericksburg, Virginia) to His Family Detailing the Battle of Chancellorsville - May 15, 1863 [Photograph].” Letters (correspondence). Civil War Collection, 1863. Box 1, Folder 42. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/679573n6wk-cor.