Westward Expansion (1801-1861)
Westward expansion began in earnest in 1803. Thomas Jefferson negotiated a treaty with France in which the United States paid France $15 million for the Louisiana Territory – 828,000 square miles of land west of the Mississippi River – effectively doubling the size of the young nation. The lands acquired stretched from the Mississippi River to the Rocky Mountains and from the Gulf of Mexico to the Canadian border. Jefferson later owned that he had “stretched the Constitution until it cracked” to acquire Louisiana. As soon as the treaty was signed, he sent Meriwether Lewis and William Clark with their Corps of Discovery to find a route to the Pacific Ocean. They returned, with their mission completed, in 1806. American artists explored this new territory and chronicled the settlement of the frontier: landscapes extolling the nation's geographic wonders from Niagara Falls to the Grand Canyon drove and documented westward expansion.