South Carolina is one of the original thirteen colonies founded by the British in the United States. It was founded as a province in 1629 by Charles I. At the time it took up modern day Tennessee, Georgia, North Carolina, and South Carolina, but grew smaller overtime. It eventually became the eigth state to enter the Union between the states underneath the US consitution. It split from the US during the civil war and is famous for being the first state to secede from the US, making it the proctor for the whole war in some people's minds. In the modern day South Carolina is still a part of the United States and one of the main states people think of when they think of the South.
South Carolina is mentioned once in Real Wales in which it is said "Wales, I never heard of that place (conversation between the author and some picnicking black Americans on the coast of South Carolina)". This sentence is likely about more than just South Carolina. It is to show the ignorance of people both in the US and even in Europe about the existence of Wales. It goes along with the modern idea of Americans not knowing geography very well as well.
Click HERE for a map of South Carolina