The primary objective of the Lewis and Clark Expedition, which took place from 1804 to 1806, was to explore and map the newly acquired territory of the Louisiana Purchase. Commissioned by President Thomas Jefferson, the expedition aimed to find a practical route to the Pacific Ocean and establish trade with Native American tribes along the way. Additionally, the expedition sought to gather scientific data and document the flora, fauna, and geography of the region. Led by Meriwether Lewis and William Clark, the exploration defined the boundaries of the western United States and paved the way for future exploration and settlement.