Southerners did not trust Republicans to protect slaves' rights so some Southern states started to wonder about secession (withdrawal from the Union ) while members of Congress tried to prevent it. On Dec. 20, 1860 South Carolina voted to secede. It was also the first to secede from union.
Senator John Crittenden of Kentucky wanted to add a series of amendments to the Constitution but the Republicans and leaders in the South rejected. No human power could save the union.
Senator John Crittenden of Kentucky
February 1861 Louisiana, Texas, Florida, Mississippi , Alabama, Georgia, joined South Carolina and seceded. The delegates from those states met and made a new nation. They called themselves the Confederate States of America and chose Jefferson Davis as their president.
President Jefferson Davis
The Southern States used states' rights to justify secession. Buchanan sent a message to Congress and said the states had no right to secede but he had no power to stop them. Lincoln's Inaugural Address was directly toward the states.
Lincoln received a message the Commander of Fort Sumter and warned they were low on supplies and Confederates surrendered. Lincoln would send an unarmed group with supplies but Davis ordered forces to attack Fort Sumter before the Union would give them supplies.