MLA
Hart, Henry W. Letter Written by Henry W. Hart (Fort Barrancas, Florida) to His Wife, Margaret Elizabeth Black Hart. Hart Enlisted in the 2nd Connecticut Light Battery, in That Same Year, Serving in the Union Army until His Battery Was Mustered out August 9, 1865 and He Was Discharged August 10, 1865. He Comments on Such Aspects of Daily Life in the Army as Food Shortages, Lack of Pay, Disease, Various Battles, and Interest in Religion - March 6, 1865 (Typescript). 1865. Stuart A. Rose Manuscript, Archives, and Rare Book Library, Box 19, Folder 32. https://digital.library.emory.edu/purl/668x95x7gt-cor.
APA, 6th edition
Hart, H. W. (1865). Letter written by Henry W. Hart (Fort Barrancas, Florida) to his wife, Margaret Elizabeth Black Hart. Hart enlisted in the 2nd Connecticut Light Battery, in that same year, serving in the Union Army until his battery was mustered out August 9, 1865 and he was discharged August 10, 1865. He comments on such aspects of daily life in the army as food shortages, lack of pay, disease, various battles, and interest in religion - March 6, 1865 (typescript) (Box 19, Folder 32) [Letters (correspondence)]. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/668x95x7gt-cor.
Chicago
Hart, Henry W. “Letter Written by Henry W. Hart (Fort Barrancas, Florida) to His Wife, Margaret Elizabeth Black Hart. Hart Enlisted in the 2nd Connecticut Light Battery, in That Same Year, Serving in the Union Army until His Battery Was Mustered out August 9, 1865 and He Was Discharged August 10, 1865. He Comments on Such Aspects of Daily Life in the Army as Food Shortages, Lack of Pay, Disease, Various Battles, and Interest in Religion - March 6, 1865 (Typescript).” Letters (correspondence). Civil War Collection, 1865. Box 19, Folder 32. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/668x95x7gt-cor.