South Carolina is a Southeastern U.S. state bordered by North Carolina, Georgia, and the Atlantic Ocean, with a population of 5.12 million and its capital in Columbia (though Charleston is its most populous city). Named for King Charles I (from the Latin Carolus), it became a royal colony in 1719 and was the eighth state to ratify the U.S. Constitution in 1788. As a slave state, it was the first to secede from the Union in 1860, fought for the Confederacy, and was readmitted in 1868. Today, its economy thrives on aerospace, automotive manufacturing, and tourism, with a GDP of $213.45 billion. Geographically, it spans from the Atlantic coastal plain to the Blue Ridge Mountains, featuring a humid subtropical climate and the Sea Islands. Human activity in the region dates back 50,000 years, and Spanish explorers first arrived in 1521, encountering powerful Native American nations like the Cherokee and Catawba.