Slavery became a larger issue in light of the Civil War starting to begin. However, slavery did not start the Civil War. That came about through many different issues with the economy and state's rights. Slavery was the straw to break the camel's back really.
The north considered the main issue in the war to be slavery. The south considered the main issue in the war to be state's rights. So as you see they weren't even fighting over the same issues!
California.
state rights over the issue of withdrawal from the union and the issue of slavery
the issue of slavery became important again in 1850. At that time, california requested to join the union as a free state.
It is likely that they wished for each state to make the decision on the legality of slavery. That would be the proper 'state's rights' position for the period.
Fighting broke out in Kansas after the government sided with the pro-slavery South during the mid-19th century. This conflict, known as "Bleeding Kansas," was marked by violent confrontations between pro-slavery and anti-slavery factions. Tensions escalated as both sides sought to influence whether Kansas would enter the Union as a free or slave state. The turmoil was a precursor to the larger Civil War.
Fighting broke out in Kansas after the government sided with the South, leading to violent conflict between pro-slavery and anti-slavery factions. This period, known as "Bleeding Kansas," saw Union supporters establish their own government in opposition to the pro-slavery forces. The tensions highlighted the deep divisions in the country leading up to the Civil War.
It was a Northern State that was pro slavery and anti Confederacy. It did not view the civil war as a slave issue. It considered the civil war a states rights issue.
Missouri
It made the issue even more prevalent. People had the decision to make a state free or a slave state.
To preserve State's Rights, particularly as they referred to slavery