What major social issue was a catalyst leading to the Civil War?

The catalyst leading to the Civil War was slavery, which was a deeply entrenched social and economic issue in the United States during the 19th century. The institution of slavery created significant divisions between the Northern and Southern states. The South's economy heavily relied on agriculture, particularly cotton production, which was dependent on slave labor. In contrast, the Northern states were increasingly moving towards industrialization and were opposed to the expansion of slavery into new states and territories.

This moral and economic conflict escalated as debates intensified over whether new states admitted to the Union would be free or slave states. Key events, such as the Missouri Compromise, the Compromise of 1850, and the Kansas-Nebraska Act, highlighted these tensions. The abolitionist movement gained momentum in the North, leading to further discord. Harsh reactions to acts of resistance, such as the Dred Scott decision and John Brown's raid, deepened the divide.

Ultimately, the question of slavery was not just a political issue but a fundamental moral dilemma that led to the secession of Southern states and the outbreak of the Civil War. It fundamentally shaped the nation's history and identity, establishing slavery as the primary catalyst for conflict during this tumultuous period.