1Thomas Jefferson to Peter S. Du Ponceau, 6 November 1817 (Jefferson Papers)
American Philosophical Society, Historical and Literary Committee; and W. Byrd manuscripts [index...
2Thomas Jefferson to Peter S. Du Ponceau, 17 January 1818 (Jefferson Papers)
American Philosophical Society, Historical and Literary Committee; and W. Byrd manuscripts [index...
3Thomas Jefferson to Peter S. Du Ponceau, 19 February 1818 (Jefferson Papers)
American Philosophical Society, Historical and Literary Committee; and W. Byrd manuscripts [index...