What was the Lewis and Clark expedition officially called?

The Lewis and Clark expedition was officially called the Corps of Discovery Expedition.

President Thomas Jefferson commissioned the expedition after the Louisiana Purchase in 1803. Meriwether Lewis and William Clark led the group, which left the St. Louis area in 1804 to explore the newly acquired western lands and seek a practical route to the Pacific Ocean.

The Corps of Discovery traveled up the Missouri River, crossed the Rocky Mountains, descended the Clearwater and Columbia rivers, and reached the Pacific coast in 1805. It returned to the United States in 1806 after gathering maps, plant specimens, animal observations, and information about the region.

The expedition depended on assistance and diplomacy involving numerous Native American nations. Sacagawea traveled with the group and served as an interpreter and guide in several situations, although the expedition’s leadership remained with Lewis and Clark.