How did the Mexican-American war affect the Missouri Compromise?

Question

When claiming statehood, the territories in the southwest gained through the war claimed lands on both sides of Missouri's border which caused unbalance between free and slaveholding states.
The territories gained through the Mexican-American war increased the population in Missouri, and the population reduction reached during the earlier compromise was no longer needed or wanted.
Almost half of the territories gained during the war were Canadian territories, which resumed the arguments in Congress about which territories should be admitted as new states and which should not.
Because France fought with the United States during the war, their government felt the debt owed to them by America should increase and should be included as part of a new compromise between the countries.

Answer 1

The Mexican-American War (1846-1848) had significant implications for the political landscape of the United States, particularly concerning the issue of slavery and the Missouri Compromise of 1820. Here's how the war affected the situation:

1. Territorial Expansion and Slavery: The territories acquired as a result of the Mexican-American War included present-day California, Arizona, New Mexico, Nevada, Utah, and parts of Colorado and Wyoming. This expansion reignited fierce debates over slavery, as both pro-slavery and anti-slavery factions sought to influence whether these new territories would permit slavery.

2. Imbalance Between Free and Slave States: The Missouri Compromise had established a delicate balance between free and slave states, admitting Missouri as a slave state but prohibiting slavery in the northern part of the Louisiana Purchase (north of the 36°30' parallel). The new territories from the war threatened to disrupt this balance. As they sought statehood, the question arose whether they would enter as free or slave states, leading to increasingly contentious debates in Congress.

3. The Compromise of 1850: The tensions surrounding the new territories contributed to the eventual creation of the Compromise of 1850, which attempted to address these issues by allowing California to enter as a free state while creating the territories of New Mexico and Utah with the question of slavery left to popular sovereignty. This was a departure from the terms of the Missouri Compromise and highlighted the inability of previous compromises to resolve the mounting sectional conflict.

4. California Gold Rush: The discovery of gold in California in 1848 accelerated the population growth in the area, prompting it to seek statehood quickly. The desire to enter as a free state intensified sectional conflicts, further complicating the legacy of the Missouri Compromise.

Overall, the Mexican-American War intensified the sectional discord over slavery, undermining the Missouri Compromise and contributing to the political landscape that would eventually lead to the Civil War. The options you presented do not accurately reflect the historical consequences of the war on the Missouri Compromise. The main takeaway is that the new territories exacerbated the divisions over slavery and led to significant legislative efforts to address the issues of statehood and the balance of power between free and slave states.