On December 20, 1860 South Carolina voted to secede, or withdrawal, from the U.S. Republicans had promised not to stop slavery but Southerners didn't trust them to protect their rights. Congress didn't like the idea. Senator John Crittenden suggested a series of amendments to the Constitution to protect the Missouri Compromise. Republicans rejected the idea.
By February 1861, Texas, Louisiana, Mississippi, Alabama, Florida, and Georgia had joined South Carolina in secession. Calling themselves the Confederate States of America, they chose Jefferson Davis as their president.Not all white Southerners welcomed secession. But, some loved the idea.
Soon after Lincoln took office a battle broke out between the Union and the Confederate States. The Union lost that battle, Fort Sumter, by surrendering on April 14th. This resulted in Virginia, Arkansas, Tennessee, and North Carolina seceded from the Union as well.