This is a fascinating interactive New York Times piece, showing where people in each state were born by census figures (from 2010, back to 1900).
As of 2010, 58% of South Carolinians were born in South Carolina (down from 91% in 1940).
5% were born in North Carolina
4% were born in New York
3% were born in Georgia
7% were born in Southern states other than SC, NC and GA
7% were born in Northeastern states other than NY
6% were born in the Midwest
3% were born in the West
6% were born outside the United States (compare that to less than 1% in 1940 and before)
http://www.nytimes.com/interactive/2...South_Carolina