1Victor du Pont and Eleuthère I. du Pont de Nemours to Thomas Jefferson, 11 August 1817 (Jefferson Papers)
2Thomas Jefferson to Eleuthere I. du Pont de Nemours, 9 September 1817 (Jefferson Papers)
3Marc Antoine Jullien to Thomas Jefferson, 30 November 1817 (Jefferson Papers)
4Thomas Jefferson to Marc Antoine Jullien, 23 July 1818 (Jefferson Papers)