Apiece of legislation that called for popular sovereignty to decide the slavery issue was

A piece of legislation that called for popular sovereignty to decide the slavery issue was the Kansas-Nebraska Act. That act set up Kansas and Nebraska as states, but slave states wanted them both to be slave-owning while free states wanted them both to prohibit slavery. To remedy this, the act stated that both state would vote upon whether they wanted to be slave states or not. This resulted in a massive influx of slave and free supporters into the region to change the vote, oftentimes resulting in violence.

Not sure this is a hard one huh