What was the alternative to The Missouri Compromise?

The alternative to the Missouri Compromise was the idea of popular sovereignty, which proposed that the settlers of a territory should decide for themselves whether to allow slavery. This concept was notably championed in the Kansas-Nebraska Act of 1854. Unlike the Missouri Compromise, which established a clear geographical line for slavery's expansion, popular sovereignty led to increased tensions and conflict, particularly in "Bleeding Kansas," as pro- and anti-slavery factions clashed over the issue.