MLA
McCabe, W. Gordon (William Gordon), 1841-1920. Letter from William Gordan McCabe (Richmond, Virginia) to General William E. Mickle, declining an invitation to attend the United Confederate Veterans event - November 14, 1911. November 14, 1911. Civil War Collection. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/378tb2rcpz-cor.
APA, 6th edition
McCabe, W. Gordon (William Gordon), 1841-1920. (November 14, 1911)[Letter from William Gordan McCabe (Richmond, Virginia) to General William E. Mickle, declining an invitation to attend the United Confederate Veterans event - November 14, 1911]. Civil War Collection, Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/378tb2rcpz-cor.
Chicago
McCabe, W. Gordon (William Gordon), 1841-1920, Letter from William Gordan McCabe (Richmond, Virginia) to General William E. Mickle, declining an invitation to attend the United Confederate Veterans event - November 14, 1911, November 14, 1911, Civil War Collection, Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/378tb2rcpz-cor.