kansas was first settled by americans in 1827 when fort leavenworth was built. in the 1850s, many more people came to live in kansas. this was also when people were fighting about slavery. people were allowed to move to kansas in 1854 because of the kansas–nebraska act. when this happened, anti-slavery free-staters from new england and pro-slavery people from missouri quickly came to kansas. they wanted to decide whether kansas would become a free state or a slave state. because of this, a lot of fighting happened, and it was known as bleeding kansas. the anti-slavery people won. on january 29, 1861, kansas entered the union as a free state.