The timeline of Kansas details past events that happened in what is present day Kansas. Located on the eastern edge of the Great Plains, the U.S. state of Kansas was the home of sedentary agrarian and hunter-gatherer Native American societies, many of whom hunted American bison. The region first appears in western history in the 16th century at the time of the Spanish conquest of Mexico, when Spanish conquistadores explored the unknown land now known as Kansas. It was later explored by French fur trappers who traded with the Native Americans. It became part of the United States in the Louisiana Purchase of 1803. In the 19th century, the first American explorers designated the area as the "Great American Desert."