What significant legislation was proposed to address the extension of slavery into new states?

The Missouri Compromise was a significant piece of legislation aimed specifically at addressing the contentious issue of the extension of slavery into new states. Proposed in 1820, this compromise was a response to the request from Missouri to join the Union as a slave state. The legislation maintained a delicate balance between free and slave states by admitting Missouri as a slave state and Maine as a free state, thus keeping the Senate divided evenly between the two factions.

Furthermore, the compromise established a geographic boundary at the 36°30' parallel. It dictated that any future states admitted from the Louisiana Territory north of this line would be free, while those south of the line would be open to slavery. This was a crucial attempt to quell the rising tensions over the expansion of slavery, although it ultimately only served as a temporary solution.

In contrast, other options reflect different contexts or later developments concerning slavery. The Compromise of 1850 sought to address various sectional conflicts, including the admission of California and the issue of slavery in the territories gained from Mexico but came after the Missouri Compromise. The Kansas-Nebraska Act, enacted in 1854, further impaired the Missouri Compromise by allowing new territories the choice of slavery based on popular sovereignty, thus escalating tensions. The