Virginia
The five largest reported ancestry groups in Virginia are: African (19.6%), German (11.7%), unspecified American (11.4%), English (11.1%), and Irish (9.8%).
South Carolina
The five largest ancestry groups in South Carolina are African American (29.5%), American (13.9%), English (8.4%), German (8.4%) and Irish (7.9%).
There is no mention of Scots or Irish in Missisipi, but I guess usquebaugh is more a 'book word ' in this case. Anyway, I've seen William Faulkner was a prolific writer so I'll be happy to drain a few more books from the library.
What is your statistical source?
What is meant by American?
What distinguishs an African from an African-American?
Some 40 years ago, I lived in South Carolina for four years. Today I live in North Carolina. In the interim, I have lived in Pennsylvania, Colorado, Tennessee, Mississippi, and Alabama. [And, before South Carolina, there were residencies in Texas, Illinois, California and Japan.]
In the USA, the census is conducted each decade. Therefore, the statistical data applies technically only to the last year of each decade (2000, 1990, 1980, 1970, 1960, 1950, 1940, 1930, etc.) Also, the data depends also upon the questions asked. Before the origin of the predecessor of IBM, the census was only a literal head count. After "IBM," up to 240 different statistical datum could be obtained.
My ancestors can be traced to England, Scotland, Ulster (Northern Ireland), Germany, France and Switzerland.
How would that affect your statistics for South Carolina? Mississippi?