ミズーリ妥協
At the time of the City of Kansas's incorporation, Missouri was still a slave state. However, the population was deeply divided over the issue of slavery. In 1854, the United States Congress passed the Kansas–Nebraska Act, which rejected the 1820 Missouri Compromise and allowed new territories to choose whether they wished to allow slavery, whereas the Missouri Compromise had prohibited slavery in any new states to be created north of latitude 36°30'. Thus, according to the Missouri Compromise, Kansas Territory (located immediately to the west of the City of Kansas, Missouri) had been a free territory but now could choose to permit slavery.