Who co-led the Lewis and Clark Expedition with Meriwether Lewis?

William Clark co-led the Lewis and Clark Expedition with Meriwether Lewis.

President Thomas Jefferson commissioned the Corps of Discovery in 1803, soon after the Louisiana Purchase. Jefferson selected Army captain Meriwether Lewis to lead the mission, and Lewis invited William Clark, an experienced Army officer and mapmaker, to serve as co-leader. Clark held the rank of second lieutenant during the expedition.

The expedition left Camp Dubois in Illinois on May 14, 1804. Its members traveled up the Missouri River, crossed the Rocky Mountains, reached the Pacific Ocean in 1805, and returned to St. Louis in September 1806. The journey lasted 862 days and produced maps, scientific observations, and reports about the lands west of the Mississippi.

The expedition is commonly called “Lewis and Clark,” but it included many other people, including the Shoshone interpreter Sacagawea and York, an enslaved man held by Clark. The mission was not the first non-Indigenous crossing of the continent, but it was the first major U.S.-sponsored exploration of the new western territory.