1Wilson Cary Nicholas to Thomas Jefferson, 22 March 1816 (Jefferson Papers)
geology; of Va. [index entry]
2Thomas Jefferson to Benjamin Henry Latrobe, 16 July 1817 (Jefferson Papers)
geology; of Va. [index entry]
3Benjamin Henry Latrobe to Thomas Jefferson, 24 July 1817 (Jefferson Papers)
geology; of Va. [index entry]
4Richard Young to Thomas Jefferson, 11 May 1820 (Jefferson Papers)
geology; of Va. [index entry]