The primary objective of the Lewis and Clark expedition, which took place from 1804 to 1806, was to explore and map the newly acquired western territories of the United States following the Louisiana Purchase. Commissioned by President Thomas Jefferson, the expedition aimed to find a practical route to the Pacific Ocean, establish trade relations with Native American tribes, and gather scientific and geographical knowledge about the vast, uncharted lands. Led by Meriwether Lewis and William Clark, the journey offered invaluable insights into the natural resources and inhabitants of the American West, paving the way for westward expansion.