Answer :
Popular sovereignty revolves around the idea that the people of a specific country/territory get to decide on certain issues.
This concept was used several times throughout American history. In the Compromise of 1850, the New Mexico and Utah territories used popular sovereignty in order to decide whether or not slavery existed in their territories. This concept was also used in the Kansas-Nebraska Act of 1854, as citizens of the Kansas and Nebraska territories got the chance to vote on whether slavery would exist in their territories.
In overall, the political doctrine of Popular Sovereignty holds that all political power (authorities of states and federal government) is inherent in the people, that is to say, people create and determine the nature of its government, gives consents to it and sustains it. They tend to accomplish this by electing their representative (individuals that advocate for their needs, desires, and projects as a society) through fair elections.