MLA

Koch, Frederick R. (Frederick Robinson). Illustrated story. Box 25, folder 549. 1842 Feb 28. https://collections.library.yale.edu/catalog/10033964.

APA, 6th edition

Koch, Frederick R. (Frederick Robinson). (["Box 25, folder 549"])(1842 Feb 28)[Illustrated story]. https://collections.library.yale.edu/catalog/10033964.