What popular sovereignty principle did Stephen Douglas promote in the context of slavery?

Stephen Douglas promoted the principle of popular sovereignty as a way to address the issue of slavery in the territories. This principle asserted that the settlers of a territory should have the right to determine whether they would allow slavery or not. Douglas believed that local populations should have control over their own affairs, including the decision of whether to permit slavery within their borders.

By advocating for states to decide on slavery, Douglas sought to create a more democratic process regarding the status of slavery in newly formed states and territories. This approach was intended to reduce sectional tensions by allowing each territory to make its own choice. Douglas's stance was notably highlighted during the debates surrounding the Kansas-Nebraska Act of 1854. The act reversed the Missouri Compromise, which had previously established a line dividing free and slave states, thus allowing for the potential expansion of slavery based on the will of the local populace.