The Lewis & Clark Expedition of 1804-06 was the greatest act of exploration in the history of the U.S. This historic enterprise explored the Western U.S. along a route beginning near St. Louis & traveled up the Missouri River, over the Rocky Mountains to the Pacific Ocean at the mouth of the Columbia River & had several return routes. Pres. Thomas Jefferson planned the enterprise, assisted by members of the nation's first & most distinguished learned society, The Amer. Philosophical Soc. (APS). This set, issued by the APS, includes 3 facsimile vol. from the Expedition. Codices: Codex A -- Clark, Jrnl, 5/13/04-8/14/04, Codex E -- Lewis, Jrnl. 5/24/05-7/16/05, & Codex J -- Lewis, Jrnl., 1/1/06-3/20/06. Includes a 30-page introduction. Unique!