Northerners saw this as a deliberate effort to bring more slave states into the Union, while Southerners felt it did not go far enough in stating what states would enter free and what would enter as slave states. The debate in the House and Senate was so emotional, that fights broke out on the floors. Eventually, the bill, with the repeal of the Missouri Compromise passed, and the new territories of Kansas and Nebraska came into the Union. It forced an even deeper wedge between Northern and Southern legislators, and many people were so disgusted with the agreement that they split off from both parties. They began to form a new political party, the Republican Party, which would come together to nominate Abraham Lincoln, who had spoken out against slavery during his campaign, but as McPherson notes, "He had condemned slavery as a moral evil but deprecated radical action against it" (McPherson, 2001, p. 131). Just...

Thus, there were many underlying causes to the Civil War, but they all came back to slavery.
In conclusion, the Civil War came about for any number of compelling reasons, but as this argument indicates, most of those had at least some root in the institution of slavery. Slave ownership divided the country, created political turmoil, and finally led to the Civil War. There were certainly other factors, but slavery was the underlying factor in common in all of them, and so, slavery, and the maintenance of the institution in the South, was the major cause of the Civil War, and a major source of unrest in the country for decades before war broke out.

References

McPherson, J.M. (2001). Ordeal by fire:…