What was the assault upon this military outpost marked the beginning of the civil war?

The assault on Fort Sumter, located in Charleston Harbor, marked the beginning of the American Civil War on April 12, 1861. Confederate forces fired on the fort, which was held by Union troops, following South Carolina's secession from the Union. The bombardment lasted for 34 hours, ultimately leading to the surrender of Union forces. This event galvanized both the North and South, leading to widespread enlistment and the escalation of hostilities.