What event prompted the south to seceded from the union?

In the prelude-months before the formal beginning of the American Civil War, the event that prompted South Carolina to secede from the Union was the election of Abraham Lincoln as the 16th President of the United States. With Lincoln's strong anti-slavery sentiments well-known throughout the nation, South Carolina anticipated further attacks upon its slave-holding way of life; therefore, it chose to secede from the Lincoln-led Union rather than endure these anticipated attacks.