Lewis and Clark cross the continent

Meriwether Lewis and William Clark led an expedition from near St. Louis to the Pacific Coast. Sacagawea, a Shoshone woman, traveled with them and helped with diplomacy and guidance.

Context

President Thomas Jefferson commissioned the expedition after the Louisiana Purchase in 1803, with goals including mapping the Missouri River, searching for a water route to the Pacific, studying plants, animals and peoples, and establishing contact with Native nations. The party left the St. Louis area in May 1804.

The Corps wintered at Fort Mandan in present-day North Dakota, where they met the French-Canadian trader Toussaint Charbonneau and his wife Sacagawea, who joined as an interpreter with her infant son. Her knowledge of Shoshone language and her presence helped signal peaceful intentions and secure horses for crossing the Rockies. Expedition accounts credit her contributions in several specific encounters, though her role is sometimes exaggerated in popular accounts.

The party reached the Pacific near the mouth of the Columbia River in late 1805, wintered at Fort Clatsop, and returned to St. Louis in September 1806. They found no easy water route across the continent but produced maps and detailed journals describing dozens of Native nations and many species new to science. Only one member, Sergeant Charles Floyd, died on the trip.

The journals kept by Lewis, Clark and several sergeants are the main sources and are now widely published.