1Thomas Jefferson to Francis Eppes, 27 June 1821 (Jefferson Papers)
2Destutt de Tracy to Thomas Jefferson, 22 February 1821 (Jefferson Papers)
3Thomas Jefferson to Destutt de Tracy, 26 December 1820 (Jefferson Papers)
4Robert Walsh to Thomas Jefferson, 20 April 1818 (Jefferson Papers)
5Destutt de Tracy to Thomas Jefferson, 11 April 1818 (Jefferson Papers)
6Robert Walsh to Thomas Jefferson, 12 March 1818 (Jefferson Papers)
7Thomas Jefferson to Robert Walsh, 19 February 1818 (Jefferson Papers)
8Robert Walsh to Thomas Jefferson, 27 January 1818 (Jefferson Papers)
9Thomas Jefferson to Robert Walsh, 9 January 1818 (Jefferson Papers)
10Thomas Jefferson to Destutt de Tracy, 15 May 1817 (Jefferson Papers)