From Ohio History Central
Popular sovereignty is a political term that simply means that the �people are the rulers.� This term is usually used in reference to political issues that are settled by popular vote or to governments based on the concept of democracy. The concept of popular sovereignty manifested itself during the Enlightenment.
During the nineteenth century, the issue of slavery gripped the United States. Rather than confronting the slavery issue directly, federal government leaders routinely avoided the slavery debate by forming compromises that utilized popular sovereignty. Rather than dictating whether or not a territory or state would or would not have slavery, government officials permitted people residing within a territory or state to decide the issue for themselves by popular vote.
The federal government utilized popular sovereignty in both the Compromise of 1850 and again in the Kansas-Nebraska Act of 1854. In the case of the Compromise of 1850, the federal government authorized citizens of the New Mexico Territory, if they ever applied for statehood, to utilize popular sovereignty to determine whether or not slavery would exist within the state�s borders. The United States outlawed slavery before New Mexico applied for statehood. With the Kansas-Nebraska Act, the federal government authorized residents of the Kansas and the Nebraska Territories to use popular sovereignty. Kansas applied for statehood first, and pro and anti-slavery advocates resorted to violence to guarantee that their respective sides would win the popular vote. As a result of this violence, usually referred to as Bleeding Kansas, it became clear to most Americans and government leaders that popular sovereignty was an unlikely solution to the slavery issue.