Which factor was a significant contributor to tensions leading up to the American Civil War?

Disputes over states' rights and slavery were a significant contributor to the tensions leading up to the American Civil War because they encapsulated the differing political, economic, and social ideologies between the North and the South.

In the South, the economy was heavily reliant on agriculture and the institution of slavery, which was integral to maintaining this economic model. Southern states believed they had the right to govern themselves and decide whether to allow slavery without federal interference. Conversely, the Northern states, which were increasingly industrialized and moving toward abolition, believed in a more centralized government that could impose laws restricting slavery.

This fundamental disagreement over the role of the federal government and the rights of individual states to make their own laws, especially regarding slavery, created a clear rift. The inability to reconcile these differences led to increasing sectionalism, where both sides became more entrenched in their views, culminating in the outbreak of the Civil War.

While economic prosperity, the expansion of railroads, and social issues like the abolition of alcohol were relevant topics of the time, they did not drive the conflict as directly as the contentious issues surrounding states' rights and slavery.