The correct answer is Kansas.
In 1854, Congress passed the Kansas-Nebraska Act. This law allowed citizens of Kansas to vote on whether or not they wanted slavery. This law worked horribly and caused a significant amount of violence in Kansas.
The law became controversial because citizens who did not want slavery argued that the election was rigged, as individuals came from Missouri to vote for slavery. These claims caused controversy between the people who wanted Kansas to be a free state and those who wanted it to be a slave state. This resulted in essentially a small civil war. This era in Kansas history became known as "Bleeding Kansas."
