What was the main purpose of Lewis and Clark's expedition?

The primary purpose of Lewis and Clark's expedition was to explore the western territories of the United States following the Louisiana Purchase in 1803. Commissioned by President Thomas Jefferson, the expedition aimed to map the newly acquired land, establish relations with Indigenous tribes, and ascertain the feasibility of a water route to the Pacific Ocean. This exploration provided invaluable information about the geography, biology, and native peoples of the region, which would play a crucial role in the westward expansion of the United States.

While other options might touch on aspects of the era, such as trade or military considerations, the essence of the expedition was focused on exploration and scientific inquiry, driven by a desire to better understand the vast and largely uncharted western expanse. This exploration laid the groundwork for future settlement and development of the American West.