The Kansas-Nebraska Act of 1854 dealt with the issue of slavery and the boundary line. The number of free states and the number of slave states had to be equal so that one could not overthrow the other according to the Missouri Compromise. The Kansas-Nebraska Act overturned the Missouri Compromise saying that each state had the right to determine whether it was a free or slave state through popular sovereignty. Because of this decision, an act of violence occurred called "Bleeding Kansas".
What happened was people that were supporters of free states came in and the people who were supporters of slave states came in trying to influence the decision of the residents. When you have two groups of people with different ideas in the same area it results in a disagreement. The problem was that this disagreement turned deadly as a major fight broke out and ended with people killed, mortally wounded, or other injuries.
