What was the immediate effect of the confederacy firing on fort sumter

The bombardment of Fort Sumter by the South Carolina militia on April 12, 1861, is seen as the first battle of the Civil War.

There was a Union garrison on the small island where the fort was located in the Charleston Harbor. After 34 hours of fire exchange, the Union unit of 87 men surrendered. The fort was then occupied by Confederate forces and remained there for four years, resisting attacks. The bombardment of the fort triggered the Civil War. In the aftermath, president Abraham Lincoln issued a call for volunteers to join the army and suffocate the rebellion; more southern states joined the Confederacy (Virginia, Tennessee, North Carolina).