Germans were a major pioneer group to migrate to Appalachia, settling mainly in western Pennsylvania and southwest Virginia. Smaller numbers of Germans were also among the initial wave of migrants to the southern mountains. In the 19th century, Welsh immigrants were brought into the region for their mining and metallurgical expertise, and by 1900 over 100,000 Welsh immigrants were living in western Pennsylvania alone. Thousands of German-speaking Swiss migrated to Appalachia in the second half of the 19th century, and their descendants remain in places such as East Bernstadt, Kentucky, and Gruetli-Laager, Tennessee. The coal mining and manufacturing boom in the late 19th and early 20th centuries brought large numbers of Italians and Eastern Europeans to Appalachia, although most of these families left the region when the Great Depression shattered the economy in the 1930s. African Americans have been present in the region since the 18th century, and currently make up 8% of the ARC-designated region, mostly concentrated in urban areas and former mining and manufacturing towns; the African-American component of Appalachia is sometimes termed Affrilachia.