As the United States expanded and acquired new states, the South wanted to have slavery in the new territories, as well as keeping it intact in the South. In contrast, most Northerners were in favor of completely abolishing slavery while others liked the idea of keeping slavery in the South, but stopping it from expanding to the new territories. Tension rose between the North and the South because of manifest destiny. In 1820, the Missouri Compromise was passed because of the conflict in Congress and the U.S. government. It prohibited slavery in the Louisiana Territory except within the boundaries of the new state of Missouri. This solved matters for a little while, but the question was raised again in 1850 after the Mexican-American War regarding the status of the territories acquired during the war. The Compromise of 1850 defused that tension and avoided secession or civil war and reduced sectional conflict for four years. In 1854, the Kansas-Nebraska Act created the territories of Kansas and Nebraska which opened new land for settlement. The same problems arose again but this time, they were solved through popular sovereignty. The Kansas-Nebraska Act allowed the settlers in the territories to determine through popular sovereignty whether they would allow slavery in each territory.
Despite many different compromises, manifest destiny still caused tension between the North and South. The ongoing sectional conflict continued to escalate until the start of the Civil War. It only really ended when African Americans were given full rights as United States citizens.