What event is widely recognized as the spark that ignited the Civil War?

The attack on Fort Sumter is widely recognized as the pivotal event that ignited the Civil War. On April 12, 1861, Confederate forces fired upon Fort Sumter, a Union stronghold in South Carolina, marking the first military engagement of the conflict. This act of aggression galvanized Northern public opinion, prompting President Abraham Lincoln to call for troops to suppress the rebellion, which led to an escalation in tensions between the North and South.

This event not only represented the breaking point between the two regions but also symbolized the shift from political discourse over slavery and states' rights to active military conflict. While other events, such as the raid on Harper's Ferry or the Dred Scott decision, contributed to the mounting tensions that led to the war, the attack on Fort Sumter is distinct in that it initiated direct hostilities and formally began the Civil War. This moment marked a decisive turn, leading both sides to prepare for a prolonged and violent conflict that would last for four years.