Envisaging the West: Thomas Jefferson and the Roots of Lewis and Clark

June 30, 1800 | Report William Dunbar to the American Philosophical Society, via Thomas Jefferson, read January 16, 1801. This letter, with several other missives and reports written by Dunbar, were forward by Jefferson to the American Philosphical Society, where they were read before the Society and later published in theTransactions of the Philosophical Society of Americain 1804. Dunbar describes the sign language used by Native Americans between the Mississippi River and the "Western American ocean."