MLA

Wheaton, Joseph, 1755-1828. Lafayette, Marie Joseph Paul Yves Roche Gilbert du Matier, marquis de, (1757-1834), autograph letter signed to Wheaton. Box 1, folder 16. [1825] January 19. https://collections.library.yale.edu/catalog/32528352.

APA, 6th edition

Wheaton, Joseph, 1755-1828. (["Box 1, folder 16"])([1825] January 19)[Lafayette, Marie Joseph Paul Yves Roche Gilbert du Matier, marquis de, (1757-1834), autograph letter signed to Wheaton]. https://collections.library.yale.edu/catalog/32528352.