The Kansas-Nebraska Act allowed the territories of Kansas and Nebraska to vote on whether or not they wanted slavery to exist in their states. This vote, left up to the citizens, negatively effected the Great Plains region.
This had a negative impact due to the amount of voter corruption that took place in Kansas. This voter corruption left individuals in favor of no slavery mad, as they believe it resulted in slavery winning the vote. This lead to violence in the region, now known as "Bleeding Kansas."