The Lewis and Clark Trail Captain Meriweather Lewis It is 1804. U.S. President Thomas Jefferson has asked Meriwether Lewis to lead an expedition across western North America's unknown territory for all but Indians. The goals: map the rivers, make friends with natives, open the West to trade, and look for a Northwest Passage (an easy water route from coast to coast). Lewis and his colleague William Clark have chosen a special team for the journey, and you're invited! Join this team in a virtual journey of exploration. Find out what it was like to be an early explorer. This site is from the collection of the National Geographic Society.  The Lewis and Clark Trail   Go west across America with Lewis and Clark on a journey of discovery.