What was the primary cause of the American Civil War?

The primary cause of the American Civil War was the disagreement over the institution of slavery. Slavery was deeply intertwined with the social, economic, and political fabric of the United States, particularly in the Southern states where the economy relied heavily on slave labor for agricultural production. Tensions escalated as Northern states, where abolitionist sentiments were stronger, began to challenge the existence and expansion of slavery into new territories.

The contentious debates over whether newly acquired territories from westward expansion would permit slavery further aggravated the situation. Key events, such as the Missouri Compromise, the Kansas-Nebraska Act, and the violent conflicts known as "Bleeding Kansas," highlighted the growing divide over this issue.

While economic disparities between the North and South played a role in the context of the conflict, they were often rooted in the differing economic systems that slavery upheld in the South versus industrialization in the North. Additionally, the election of Abraham Lincoln was a significant trigger; however, it was his anti-slavery platform that alarmed Southern states, leading them to secede. Thus, the central issue that drove the nation into war was fundamentally about the institution of slavery and its implications for national identity and governance.