The primary reason Thomas Jefferson sent Lewis and Clark on an expedition was to explore and document the newly acquired western territories of the United States, specifically the land acquired through the Louisiana Purchase. President Jefferson wanted to gain knowledge about the geography, flora, fauna, and Native American tribes in these territories, as well as to find a practical route for a transcontinental commerce route. Additionally, he hoped to establish American presence and sovereignty in the West, while also potentially finding a water route to the Pacific Ocean.
