MLA
Downing, George T. (George Thomas), 1819-1903. Letter to William H. Scott, Sr. from George T. Downing, January 19, 1901. January 19, 1901. William H. Scott Family Papers, 1848-1982. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/112m63xv12-cor.
APA, 6th edition
Downing, George T. (George Thomas), 1819-1903. (January 19, 1901)[Letter to William H. Scott, Sr. from George T. Downing, January 19, 1901]. William H. Scott Family Papers, 1848-1982, Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/112m63xv12-cor.
Chicago
Downing, George T. (George Thomas), 1819-1903, Letter to William H. Scott, Sr. from George T. Downing, January 19, 1901, January 19, 1901, William H. Scott Family Papers, 1848-1982, Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/112m63xv12-cor.