Encarta has an article called The Most (and Least) Educated States. The article examines ranking systems of education in states.
The map above, based on data from the article, has some geographical trends. Most of the highly college educated states range from the District of Colombia to New England. While I have not looked at the data for Virginia I am sure the Northern Virginia (NOVA) area around Washington is the reason Virginia is on the top of the list. Many people who live here worked for government, non-government organizations, and businesses that are highly intertwined with the government.
Appalachia, the central South, and the Ohio River area are some of the lowest college educated areas in America. Here many poor Whites and Blacks have lived. The plantation economy was never huge here. The area has portions of coal mining country and the Rust Belt. Nevada is proportionally low also. Many businesses in booming Las Vegas are service sector which do not require a college degree.