Final answer:
The Missouri Compromise, Compromise of 1850, Fugitive Slave Law, Kansas-Nebraska Act, Dred Scott Decision, and the issue of slavery in the Mexican Cession lands were key events that increased sectional tensions and contributed to the outbreak of the Civil War.
Step-by-step explanation:
Key Events Leading to the Civil War
The journey towards the American Civil War was marked by several critical events that exacerbated sectional tensions related to the issue of slavery. One significant event was the Missouri Compromise of 1820, which attempted to maintain a balance between slave and free states by admitting Missouri as a slave state and Maine as a free state, while establishing a boundary for the future expansion of slavery.
The Compromise of 1850 further attempted to address these tensions by including the Fugitive Slave Law, admitting California as a free state, and establishing the territories of Utah and New Mexico with the question of slavery to be determined by popular sovereignty. However, the Fugitive Slave Law stirred strong opposition in the North, as it required citizens to assist in the capture of fugitive slaves, challenging Northern sensibilities and leading to active resistance such as the Underground Railroad.
Another pivotal event was the Kansas-Nebraska Act of 1854, which effectively nullified the Missouri Compromise by allowing the territories of Kansas and Nebraska to decide the issue of slavery through popular sovereignty. This led to violent confrontations known as Bleeding Kansas, as pro-slavery and anti-slavery settlers clashed. Additionally, the Dred Scott Decision of 1857 by the Supreme Court, which ruled that African Americans could not be American citizens and that Congress had no authority to prohibit slavery in federal territories, invalidated the concept of limiting the spread of slavery and fueled fears of slavery's expansion into new territories.
Finally, the debate over slavery in lands acquired from the Mexican Cession was a hotbed for conflict. Northern and Southern states had starkly different views on whether new territories should be free or slave-holding. This unresolved discord laid the groundwork for Abraham Lincoln's election and the subsequent secession of Southern states, which ultimately led to the outbreak of the Civil War.