The first people who lived in Kansas were Native Americans who were nomadic (people who don't live in one place for very long). They hunted American bison. In the 1500s, Spanish conquistadores came to explore the place. Later, French fur trappers came to the area. They traded with the Native Americans. The United States added most of Kansas in the Louisiana Purchase in 1803. In 1854, the Kansas-Nebraska Act opened the place for Americans to move there. A lot of fighting happened because the new residents had to decide if they wanted slavery. The new residents decided to make slavery illegal. The fighting helped start the American Civil War.