Secession
When it was seen that President Abraham Lincoln would be elected, a number of conventions organized around the Deep South to discuss the options. States with strong pro-secession movements such as Alabama and Mississippi sent delegates to the convention where they advised the Carolinians to "take the lead and secede at once". On December 20, 1860, South Carolinians in Charleston voted to secede from the Union. President James Buchanan declared the secession illegal but did not act to stop it.
Six days later, on the day after Christmas, Major Robert Anderson, commander of the U.S. troops in Charleston, withdrew his men into the island fortress of Fort Sumter in Charleston Harbor. South Carolina militia swarmed over the abandoned mainland batteries and trained their guns on the island. Sumter was the key position to preventing a naval invasion of Charleston, so Carolina could not afford to allow federal forces to remain there indefinitely. More important, having the Union control its largest harbor meant that the Confederacy was not really independent.
On February 4, a congress of Southern states met in Montgomery, Alabama, and approved a new constitution for the Confederate States of America. Lincoln argued that the United States were "one nation, indivisible" and denied the Southern states' right to secede. Upper Southern states such as Virginia and North Carolina, which had not yet seceded, called a peace conference, to little effect. South Carolina entered the Confederacy on February 8, 1861 ending less than six weeks of being an independent State of South Carolina.
Read more about this topic: Republic Of South Carolina