The purpose of the Lewis and Clark Expedition, which took place from 1804 to 1806, was to explore the newly acquired western territories of the United States following the Louisiana Purchase. Commissioned by President Thomas Jefferson, the expedition aimed to map the region, establish trade with Native American tribes, and seek a practical route to the Pacific Ocean. Meriwether Lewis and William Clark led the journey, gathering invaluable information about the geography, flora, fauna, and diverse cultures of the land. Their exploration significantly contributed to the westward expansion and understanding of the American frontier.