MLA
Grant, Ulysses S. (Ulysses Simpson), 1822-1885. Official copy of telegram from General of the Army Ulysses S. Grant (Washington, D.C.) to Major General Phillip H. Sheridan directing him to preserve order and enforce the law in New Orleans - March 9, 1867. March 9, 1867. Civil War Collection. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/631cjsxmx4-cor.
APA, 6th edition
Grant, Ulysses S. (Ulysses Simpson), 1822-1885. (March 9, 1867)[Official copy of telegram from General of the Army Ulysses S. Grant (Washington, D.C.) to Major General Phillip H. Sheridan directing him to preserve order and enforce the law in New Orleans - March 9, 1867]. Civil War Collection, Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/631cjsxmx4-cor.
Chicago
Grant, Ulysses S. (Ulysses Simpson), 1822-1885, Official copy of telegram from General of the Army Ulysses S. Grant (Washington, D.C.) to Major General Phillip H. Sheridan directing him to preserve order and enforce the law in New Orleans - March 9, 1867, March 9, 1867, Civil War Collection, Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/631cjsxmx4-cor.