The Louisiana Purchase of 1803 doubled the size of the United States, adding over 800,000 square miles of land west of the Mississippi River. President Thomas Jefferson was eager to learn more about this vast new territory, and he saw the Lewis and Clark expedition as an opportunity to gather information about its geography, natural resources, and inhabitants.
2. To Establish American Sovereignty Over the West
The Louisiana Purchase had given the United States a claim to the Oregon Country, but other countries, including Great Britain and Spain, also had claims to the region. Jefferson wanted to strengthen the American claim by sending an expedition to explore the area and demonstrate American presence.
3. To Find a Water Route to the Pacific Ocean
One of the main goals of the Lewis and Clark expedition was to find a water route from the Missouri River to the Pacific Ocean. Jefferson believed that such a route would provide a valuable trade route and open up new economic opportunities for the United States.
4. To Gather Scientific Information
Jefferson was a man of science, and he was eager to learn more about the natural history of the West. He instructed Lewis and Clark to collect specimens of plants, animals, and minerals, and to make observations about the climate and geology of the region.
5. To Establish Relations with Native American Tribes
The Lewis and Clark expedition was also a diplomatic mission. Jefferson wanted to establish friendly relations with the Native American tribes in the West, and he instructed Lewis and Clark to treat them with respect and to learn about their cultures.