Excerpts from The Journals of Lewis and Clark

Edited by Bernard DeVoto

Published in 1953

By 1800 Europeans and Americans understood the basic geography of most of the world's continents, with the exception of the western two-thirds of North America, the interior of Africa, the Arctic, and Antarctica. France, England, Russia, Spain, and the United States were very interested in the region beyond the Mississippi River in North America for its commercial potential but had not yet explored it extensively. Even Native American communities knew only their immediate areas—the land that they hunted or cultivated regularly. They too lacked a continental perspective.

Thomas Jefferson, obsessed with cartography (mapmaking) and natural history, understood the necessity of exploring and mapping the vast region west of...