I detoured to this lost corner of America on a recent road trip across Pennsylvania, stopping first to see the Museum of Anthracite Coal in the Ashland borough hall. They had to turn the lights on for me when I got there, but the displays proved to be a comprehensive primer on the industry that shaped a region with the world’s highest concentration of low-ash anthracite, a prized kind of hard, clean-burning coal. It was discovered around Ashland in the 1850’s when Henry Clay, then a U.S. Senator from Kentucky, promoted the imposition of tariffs that made it profitable to replace imports from Wales with coal from the United States. Surveys revealed that northeast Pennsylvania had 75 billion tons of bituminous coal and 23 billion tons of anthracite, resulting in the growth of mining operations and small towns to serve them.