What was the official name of the U.S. expedition led by Lewis and Clark from 1804 to 1806?

The official name of the U.S. expedition led by Lewis and Clark was the Corps of Discovery.

President Thomas Jefferson commissioned Meriwether Lewis and William Clark after the Louisiana Purchase. The expedition’s formal purpose was to explore the newly acquired territory, find a practical route to the Pacific, study plants and animals, and establish relations with Indigenous nations.

The Corps of Discovery left near St. Louis in May 1804 and reached the Pacific Ocean in November 1805. It returned to St. Louis in September 1806 after traveling thousands of miles through the interior of North America.

Sacagawea joined the party with her infant son and assisted with translation and diplomacy, although the expedition depended on many Indigenous guides and communities. The journey mapped routes and gathered scientific information, but it did not mean the land was unoccupied or unknown.