Lived: 1774-1809 William Clark Lived: 1770-1838 Meriwether Lewis Meriwether Lewis was hand-picked by President Thomas Jefferson to lead the American expedition to the Pacific and explore the vast tract of territory he had recently - and some detractors said foolishly - purchased. The President sent Lewis to the finest tutors in the nation in order to sharpen his knowledge of the natural sciences and prepare him for his voyage. Enlisting William Clark, his former commanding officer, to join him in the voyage, the two journeyed from St. Louis, Missouri, across the Rockies to the Oregon territories. Arguably the most important explorers in American history, Lewis and Clark forged not only a path through the frontier, but also the beginning of a great movement westwards to fulfill what was see