Sitting astride the 14-foot Great Vein of bituminous coal, the communities of the Hocking Valley Coalfield were inextricably linked to the fortunes of a 50-year coal boom. Life in the Little Cities of Black Diamonds was not always easy or prosperous. Employment in the mines and clay plants rose and fell with economic conditions, and labor-management conflict led to strikes and violence. Even today, smoke from a mine fire, set deep underground during...