MLA
Cockrell, Francis Marion, 1834-1915. Letter from Francis Marion Cockrell (Washington) to L. Dalton - February 23, 1882. February 23, 1882. Civil War Collection. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/170msbcd49-cor.
APA, 6th edition
Cockrell, Francis Marion, 1834-1915. (February 23, 1882)[Letter from Francis Marion Cockrell (Washington) to L. Dalton - February 23, 1882]. Civil War Collection, Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/170msbcd49-cor.
Chicago
Cockrell, Francis Marion, 1834-1915, Letter from Francis Marion Cockrell (Washington) to L. Dalton - February 23, 1882, February 23, 1882, Civil War Collection, Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/170msbcd49-cor.