How did Lewis and Clark became an explorer?

Lewis and Clark became explorers after being selected to lead the Corps of Discovery expedition in 1803, commissioned by President Thomas Jefferson. Meriwether Lewis, Jefferson's personal secretary, was tasked with exploring the newly acquired Louisiana Territory and finding a practical route to the Pacific Ocean. He chose William Clark, an experienced frontiersman and mapmaker, to co-command the expedition. Together, they documented the geography, biology, and indigenous cultures of the region, significantly contributing to American exploration and expansion.