What was the idea behind popular sovereignty in the mid-1800s?

Popular sovereignty was supposed to be a solution for slavery. This is because popular sovereignty revolves around the idea of letting citizens vote on whether or not they wanted slavery to exist in their territory.

The idea behind this concept is that the people would have control over the institution of slavery. The government felt that if the people decided on the issue, there would be less fights about it. However, this was totally wrong, as the Kansas-Nebraska Act used this concept and it resulted in violence in Kansas.