The American Civil War had a warm-up game in Kansas, as Free State Advocates and Pro-Slavery Advocates rushed into the territory to influence its development. Political war figuratively broke out, and literal war also reared its ugly head as scores of men on both sides of the debate died. Many Pro-Slavery Missourians inserted themselves in both the voter fraud and violence. Yet, in the end, the secession of Southern Senators finally made it possible for Free Staters and their prospective state constitution to be adopted, leading to the Free State of Kansas joining the United States just as that Union was being dissolved by Confederate states.