1Thomas Jefferson to Alexander von Humboldt, 6 December 1813 (Jefferson Papers)
I have to acknolege your two letters of Dec. 20. & 26. 1811. by mr Correa , and am first to thank...
2Thomas Jefferson to Alexander von Humboldt, 14 April 1811 (Jefferson Papers)
The interruption of our intercourse with France , for some time past, has prevented my writing to...
3Thomas Jefferson to Alexander von Humboldt, 6 March 1809 (Jefferson Papers)
I recieved safely your letter of May 30. & with it your astronomical work & Political essay on...