1Thomas Jefferson to Andrew Ellicott, 24 June 1812 (Jefferson Papers)
geography; TJ on [index entry]
2Thomas Jefferson to Thomas W. Maury, 3 February 1816 (Jefferson Papers)
geography; TJ on [index entry]
3Thomas Jefferson to James H. McCulloh, 7 November 1817 (Jefferson Papers)
geography; TJ on [index entry]
4Thomas Jefferson to Horace H. Hayden, 15 January 1821 (Jefferson Papers)
geography; TJ on [index entry]