The brainchild of Democratic Senator Stephen A. Douglas, the Kansas-Nebraska Act of 1854 created the territories of Kansas and Nebraska and allowed for popular sovereignty in the territories. Popular sovereignty permitted American settlers to decide whether a territory (and consequently, state) would be open to slavery or not. Douglas viewed popular sovereignty as the remedy for sectional tensions over slavery; instead, this idea and the act itself inflamed his political opponents, people like Abraham Lincoln, who saw how both the idea and act in effect repealed the Missouri Compromise and thus opened the unlimited expansion of slavery.