MLA

MacDonald, George, 1824-1905. Geddes, William D.. Box 2, folder 73. 1865. https://collections.library.yale.edu/catalog/17297727.

APA, 6th edition

MacDonald, George, 1824-1905. (["Box 2, folder 73"])(1865)[Geddes, William D.]. https://collections.library.yale.edu/catalog/17297727.