Why did some Southern states secede from the United States to form the Confederacy?

Republican Abraham Lincoln was elected president in 1860 on a platform of eliminating slavery. In response, South Carolina seceded in December 1860, announcing that it was no longer part of the United States. Over the next few months, the remaining states of the deep South (Georgia, Florida, Alabama, Mississippi, Louisiana, Arkansas, and Texas) also seceded. In February 1861 delegates from these states met at Montgomery, Alabama, where they founded the Confederate States of America. The Constitution of the new Confederacy resembled the Constitution of the United States in most respects, except that it tilted the balance of power away from the national government toward the separate states. More importantly, it prohibited virtually any effort to interfere with the institution of slavery. Delegates also chose the Confederacy's first (and only) president, Jefferson Davis. He was a Mississippi slave owner who had served in the U.S. Senate and in the Cabinet prior to secession.

When Lincoln was inaugurated in March 1861, the U.S. was faced with its most severe crisis. In his First Inaugural Address, the new president urged Americans not to wage war against one another. He also reminded secessionists that, as president, he would defend the Union. Lincoln believed that states had no right to leave the Union, and he denounced secession as "the essence of anarchy."