Civil War, Reconstruction, and Industrial Growth

Sectionalism and the Road to the Civil War

During the nineteenth century, the United States experienced deep internal friction known as sectionalism. Sectionalism refers to the growing economic, social, and political divisions between the North and South. The Southern economy relied heavily on plantation agriculture and enslaved labor, primarily to produce cash crops like cotton. In contrast, the Northern economy was characterized by industrial manufacturing, commerce, finance, and free wage labor. These contrasting economic structures led to sharp political disagreements, especially regarding whether slavery should expand into newly acquired federal territories.

To manage these tensions, Congress passed several major legislative compromises. The Missouri Compromise of 1820 admitted Missouri as a slave state and Maine as a free state, while prohibiting slavery in the Louisiana Territory north of latitude 36°30′, except in Missouri. Decades later, the Compromise of 1850 admitted California as a free state and enacted a stricter Fugitive Slave Act. Political conflict flared again when the Kansas-Nebraska Act of 1854 applied popular sovereignty to those territories, allowing settlers to decide whether to permit slavery.

National divisions deepened further through court rulings and social activism. In Dred Scott v. Sandford, the Supreme Court ruled that people of African descent, whether enslaved or free, could not be U.S. citizens and that Congress could not prohibit slavery in federal territories. Meanwhile, abolitionists actively campaigned through literature, speeches, and the Underground Railroad to end slavery entirely. The crisis reached its breaking point with the election of Abraham Lincoln in 1860, which prompted South Carolina and other Southern states to secede from the Union.