In 1804-06, Captains Meriwether Lewis and William Clark led about 40 soldiers and boatmen on an epic journey. President Thomas Jefferson commissioned this "Corps of Discovery" to find a route to the Pacific Ocean through the newly acquired Louisiana territory. Along the way, they mapped the land, recorded the resources, and contracted its native inhabitants.
The landscaped has changed since Lewis and Clark explored it: rivers have been dammed, forests cut over, prairies plowed under, and roads built to the horizon. Although remnants of wilderness still exist, imagine this land as Lewis and Clark first saw it two centuries ago.
The United States purchased the Louisiana territory - more than 870,000 square miles - from France in 1803. President Jefferson selected Meriwether Lewis (far left) to lead an expedition there.
With Jefferson's permission, Lewis asked his friend and former commanding officer William Clark (left), to be co-leader. Although opposite in temperament, they worked harmoniously through out the two year journey.