When president Abraham Lincoln became president that's when the U.S was torn apart. South Carolina declared that they didn't want to be part of the Union/USA. The reason why they left the union was because they thought that Lincoln was a danger to there rights. Even though Lincoln just wanted to stop slavery from expanded westward and that they could keep their slaves. He wanted the nation to not separate. They disagreed with all this and Seceded. There new nation was called Confederate States of America.