The Lewis and Clark expedition, commissioned by President Thomas Jefferson, aimed to explore the newly acquired Louisiana Territory and find a practical route across the western portion of the United States to the Pacific Ocean. Conducted from 1804 to 1806, the expedition provided crucial geographic, scientific, and cultural information about the land, its inhabitants, and its natural resources. The journey also sought to establish trade with Native American tribes and assert U.S. sovereignty over the region. Ultimately, the expedition greatly contributed to the westward expansion of the United States and its understanding of the nation's geography.