The authors note that debate continues over exactly where Appalachia is and even how the name is pronounced.

They accept the federal definition of Appalachia as comprising all of West Virginia and parts of Mississippi, Alabama, Georgia, Tennessee, South Carolina, North Carolina, Kentucky, Virginia, Ohio, Pennsylvania, Maryland and New York, roughly following the spine of the ancient Appalachian Mountains.

But the encyclopedia also considers the impact of Appalachian migrants to other areas, including cities in the Midwest, and recent trends such as "urban Appalachia" in growing metropolitan areas and "rural sprawl" in expanding tourism enclaves of the Great Smoky Mountains.

As for pronunciation, it's "Ap-pa-LATCH-a" in the southern mountains, but more commonly "Ap-pa-LAY-cha" in the rest of the country, particularly north of the Mason-Dixon Line.