The "Kansas State Line" refers to the boundary that separates the state of Kansas from its neighboring states. It runs east to west, marking the border with Missouri to the east and Colorado to the west. This line is significant for defining the geographical and political limits of Kansas, which became a state in 1861. The state line is also important in historical contexts, particularly during the period of westward expansion in the United States. It played a role in events such as the Bleeding Kansas conflict, which was a series of violent political confrontations involving anti-slavery and pro-slavery settlers in the Kansas Territory during the 1850s.