March 3, 1803 | Letter Thomas Jefferson to William Dunbar, March 3, 1803 After thanking William Dunbar for earlier correspondence, including Martin Duralde's report to the American Philosophical Society, Thomas Jefferson expresses hopes that American rights to the Mississippi River can be maintained without war; the President also anticipates the acquisition of Native lands on the left bank of the river to "plant on the Missisipi itself the means of it's own defence."