MLA

Whitman, Walt, 1819-1892. Typescript carbon, corrected. Box 3, folder 144. [1863 Oct 21?]. https://collections.library.yale.edu/catalog/2053777.

APA, 6th edition

Whitman, Walt, 1819-1892. (["Box 3, folder 144"])([1863 Oct 21?])[Typescript carbon, corrected]. https://collections.library.yale.edu/catalog/2053777.