What event triggered the start of the Civil War?

The attack on Fort Sumter by Confederate forces is widely recognized as the event that triggered the start of the Civil War. On April 12, 1861, Confederate troops fired upon Fort Sumter, a Union fort located in Charleston, South Carolina. This assault marked the first instance of armed conflict between the North and the South, effectively signaling the breakdown of negotiations and the beginning of hostilities in the Civil War.

While the election of Abraham Lincoln played a significant role in heightening tensions between the North and the South, it did not directly initiate the war itself. Lincoln's election in 1860 led to the secession of several Southern states, but the actual commencement of fighting began with the attack on Fort Sumter. Similarly, the signing of the Declaration of Independence marked a critical moment in American history, but it occurred over 80 years prior to the Civil War and did not trigger any conflict related to it. Finally, the publication of Uncle Tom's Cabin was influential in shaping public opinion about slavery, but it was not an immediate catalyst for the outbreak of war. The decisive action at Fort Sumter clearly represents the point at which the conflict escalated into open warfare, making it the correct answer.