This is the thrilling story of two men commissioned by President Thomas Jefferson to explore the unknown land of the Louisiana Purchase—the vast, mysterious land from the Mississippi River to the Pacific Ocean. In 1803 Meriwether Lewis and William Clark gathered a crew of adventurous men of strength and ability to form the Corps of Discovery. Could they find a waterway passage through this unknown territory to the Pacific Ocean? Each man knew the trip would be hazardous, even life-threatening. How would the native Indian tribes react to them? How were they going to communicate with the Indians? What kind of land formations and dangers were waiting ahead? Captain Lewis said to assume the trip would take two years, a long time to be gone from home. They would claim the land as they went, doubling the size of the new nation, the United States of America.