Around that time, coal mines were developed in the area around Harman, Bluefield, War, and Pocahontas, which together were known as the Pocahontas Coal Fields. They helped support the Industrial Revolution in the United States. The development of the coal industry in this area created a boom in the local and national economy, and attracted immigrant European workers and enslaved/ migrant African Americans from the Deep South to the mountains in search of industrial work. During the Great War and World War II, coal from this area supplied the navies of the United States and United Kingdom.