Answer:
Lewis and Clark Expedition, ongoing between 1804 to 1806, U.S. military expedition, was led by Captain Meriwether Lewis and Lieutenant William Clark, to explore the Louisiana Purchase and the Pacific Northwest. Thomas Jefferson picked Lewis to go on all western expeditions--Lewis chose Clark due to Clark's abilities as a draftsman and frontiersman, which were even stronger than Lewis's. Lewis so respected Clark that he made him a co-commanding captain of the Expedition, even though Clark was never recognized as such by the government.