1. Territorial Expansion: The annexation of new territories, such as Texas and California, brought the question of whether slavery should be allowed in those areas. The Missouri Compromise of 1820 had attempted to strike a balance between slave and free states, but the acquisition of new territories reignited the debate.
2. Economic Interests: The economy of the Southern United States heavily relied on the institution of slavery, particularly in the agricultural sector. Many Southern planters and landowners saw slavery as a vital part of their economic success and were resistant to any efforts to abolish it.
3. Abolitionist Movement: In the North, an active abolitionist movement emerged, advocating for the immediate and unconditional abolition of slavery. Prominent abolitionists, such as Frederick Douglass, William Lloyd Garrison, and Harriet Beecher Stowe, played a crucial role in shaping public opinion and mobilizing support for the abolitionist cause.
4. Political Polarization: The issue of slavery became increasingly politicized, leading to deep divisions between the Northern and Southern states. These divisions manifested themselves in Congress and the presidential elections. The Compromise of 1850 and the Kansas-Nebraska Act of 1854 further intensified tensions and failed to resolve the underlying issues related to slavery.
5. Dred Scott Case: In 1857, the Supreme Court ruled in the Dred Scott case that African Americans, whether enslaved or free, were not U.S. citizens and could not sue in federal court. This decision further inflamed tensions and contributed to the growing divide between the North and the South.
Ultimately, the issue of slavery became a central factor in the outbreak of the American Civil War in 1861, which was fought primarily over the issue of preserving or abolishing the institution of slavery in the United States. The war resulted in the victory of the Union forces and the eventual abolition of slavery in the United States with the ratification of the 13th Amendment to the Constitution in 1865.