Which issue was a significant factor that contributed to the outbreak of the Civil War?

The issue of slavery was a significant factor that contributed to the outbreak of the Civil War due to its profound impact on American society and politics in the mid-19th century. The moral, economic, and political disputes over slavery created a deep division between the Northern and Southern states.

In the North, there was a growing abolitionist movement, alongside significant opposition to the expansion of slavery into new territories and states. The belief that slavery was morally wrong was becoming increasingly prevalent, leading to tensions with Southern states, which considered slavery essential to their agricultural economy and way of life.

The debates surrounding laws such as the Missouri Compromise and the Kansas-Nebraska Act, along with the Supreme Court's decision in the Dred Scott case, only intensified these divisions. Ultimately, the pursuit of maintaining the institution of slavery became so contentious that it led Southern states to secede from the Union after Abraham Lincoln's election in 1860, culminating in the Civil War.

While issues like taxation, immigration, and trade tariffs played roles in regional tensions, they did not hold the same paramount importance to the fundamental conflict regarding slavery, which was at the heart of the national divide leading to war.