What was the immediate conflict that sparked the civil war?

Answer 1

Lincoln's refusal to acknowledge the Confederacy, and that the US Army garrison on the island of Fort Sumter in Charleston harbour was in Confederate territory.

Answer 2

The immediate conflict that sparked the Civil War in the United States was the secession of several southern states in response to the election of Abraham Lincoln as president in 1860. Southern states feared that Lincoln, who opposed the expansion of slavery, would undermine their economic and political interests. The secession of these states and the subsequent attack on Fort Sumter by Confederate forces in April 1861 ultimately led to the outbreak of war.