Lewis and Clark Expedition

Explore Lewis and Clark's 8,000-mile journey in Google Earth.

Jefferson sent Lewis and Clark to map, trade, and secure the West

Beyond seeking a water route to the Pacific, Jefferson tasked the Corps of Discovery with mapping the new Louisiana Territory, cataloging its resources, and establishing trade with Native nations.

Clark’s maps provided the first detailed record of the American West

Covering over 8,000 miles, William Clark’s maps charted rivers, mountains, and tribal territories with remarkable accuracy. Equipped with sextants, compasses, telescopes, and more, Clark became an expert at surveying—requiring extensive celestial and topographical observations each day.

The Louisiana Purchase nearly doubled America’s size in 1803

Acquired from France for $15M, the Louisiana Purchase added 828,000 square miles to the United States—stretching from the Mississippi River to the Rockies. US ambassadors in France signed the papers to buy the tract from the embattled Napoleon Bonaparte for a mere $15M before Jefferson learned the terms, due to the advantageous nature of the deal.

Jefferson feared European control in the West of North America

Jefferson pushed for the Louisiana Purchase to prevent France or Spain from dominating the western frontier, securing control of the Mississippi River and vast lands that he felt were essential to America’s strategic and economic future.

Jefferson’s Lewis and Clark expedition joined the centuries-long hunt for Northwest Passage

For centuries, leaders pursued a direct seafaring trade route from Europe to Asia. Jefferson joined this quest by sending Lewis and Clark west, though they confirmed no such practical interior route existed across the continent.

Meriwether Lewis grew up in the same neighborhood as Jefferson

Hailing from Jefferson’s Albemarle County neighborhood in Virginia, Lewis was a trusted aide and former Army officer. After leading the Corps of Discovery, he became Louisiana Territory governor in 1806, dying three years later under mysterious circumstances.

William Clark negotiated one-tenth of all ratified treaties between Native Americans and the US.

The expedition included Clark’s enslaved servant, York

York, Clark’s enslaved servant, played a full role in the expedition—hunting, scouting, and aiding diplomacy with Native nations who were fascinated by his appearance. Despite his contributions, York remained enslaved for some time after the journey, though its uncertain if he remained so for the rest of his life. Explore every member of the Corps of Discovery here.

The Lewis and Clark expedition purchased more than 260 separate items to supply their journey.