What idea promoted the belief that individual territories could determine their own slavery status?

The concept that promoted the belief that individual territories could determine their own slavery status is known as Popular Sovereignty. This idea emerged in the mid-19th century, primarily as a political solution to the contentious issue of whether new states admitted to the Union would be free or slave states.

Proponents of popular sovereignty argued that the residents of each territory should decide for themselves whether to permit slavery or not, rather than having the federal government impose a decision. This belief was significant because it aimed to ease sectional tensions by allowing local populations to exert their preferences concerning slavery.

The implementation of popular sovereignty was notably featured in legislation such as the Kansas-Nebraska Act of 1854, which allowed territories to vote on the legality of slavery. This led to significant conflict and violence, particularly in Kansas, highlighting the complexities and challenges of applying this principle. Overall, popular sovereignty reflected a democratic approach to deciding contentious issues, but it also underscored the deep divisions within the country regarding slavery.