In 1803, Kansas was added to the United States as land from the Louisiana Purchase. The Lewis and Clark Expedition started in St. Louis. In 1804, they came to Kansas in what is today Kansas City, Kansas. They met French fur trappers who knew the land well. In 1806, explorer Zebulon Pike came to Kansas. He called it the "Great American Desert" because it had no trees or plants. The U.S. government saw Kansas as a desert too, so they sent Native Americans to it. They believed it was not good land, so they didn't care if Native Americans were sent there.