Where was the popular sovereignty and slavery in the territories?

Popular sovereignty was a principle that allowed the settlers of a territory to decide whether to permit slavery within their borders. This approach was notably applied in the Kansas-Nebraska Act of 1854, which led to violent conflicts, known as "Bleeding Kansas," as pro-slavery and anti-slavery factions clashed. The concept aimed to resolve the contentious issue of slavery's expansion into new territories but ultimately heightened tensions between the North and South, contributing to the Civil War.