Manifest Destiny set the stage for the civil war to come. Americans began moving west in search of unsettled land; with this expansion, the North and South began to debate slavery. The debate was whether slavery should be allowed in the newly created territories. The territories consisted of lands the United States received through the Missouri Compromise of 1820, the Mexican Cession of 1848, the Compromise of 1850 with Mexico, and the Gadsden Purchase of 1852 (Kennedy 388). The controversy over how slavery would be extended to these new territories as they sought statehood was the major political crisis that ultimately led to the Civil War. Popular sovereignty participated in the construction of tension between the north and the south; popular sovereignty was a doctrine which stipulated that the sovereign people of a territory should determine the status of slavery for themselves (Kennedy 378), the new doctrine, the Kansa Nebraska law, overturned the Missouri Compromise which stipulated that no state could enter when the slave states were passing. 36030. With this new law, Kansas was allowed to determine for itself whether it would enter the Union as a free or slave state. Fearing that the balance of power in the Senate would be upset if Kansas became a free state, southerners began moving into the territory in an attempt to dominate the pro-slavery vote. However, at the same time, settlers from the North were moving into the territory in an attempt to maintain its free state. Although Kansas was closer to the north and was more likely to enter as a free state, it was next to Missouri, a slave state. Because Kansas neighbored a slave state, the South believed it had a chance of entering as a slave state. Popular sovereignty being the new pol...... middle of paper ......m, while the pro-slavery South believed the federal government controlled them and limited their states' rights. The West's addition of territories annexed to the United States played an important role in the coming Civil War at the time. The addition of slavery to the territories threatened the balance of Congress. Even with the compromises the government attempted to make to maintain peace between the north and south, they did not resolve the underlying problem. Overturning the Missouri Compromise with the Nebraska Kansan Act was supposed to be a better compromise, but this action backfired on the government and led to the first bloody battle that ultimately led to a horrible civil war. Works Cited Kennedy, David M., and Lisabeth Cohen. The American Pageant: A History of the American People. Boston, MA: Wadsworth Cengage Learning, 2013. Print.