Kansas-Nebraska Act

A law passed by Congress in 1854 that divided the territory west of the states of Missouri and Iowa and the territory of Minnesota into two new territories, Kansas and Nebraska. The law was extremely controversial because it did not exclude slavery from either territory, despite the fact that the Missouri Compromise prohibited slavery in these territories. By effectively repealing the Missouri Compromise, the law outraged many northerners, led to the collapse of the Whig party and the rise of the Republican party, and moved the nation closer to civil war.