People who came from Missouri to disrupt the Kansas election decide between free and slave were called .?

The people who came from Missouri to disrupt the Kansas election and decide between free and slave were called "Border Ruffians" or "Missourians". They were proslavery men from Missouri who crossed the border into Kansas to vote illegally and influence the outcome of the election in favor of slavery. Their actions contributed to the tensions and violence that eventually led to the American Civil War.