U.S. railroads have not hauled so much crude oil since the short period at the dawn of the petroleum age, when John D. Rockefeller relied on trains to build his Standard Oil empire.
But the long, black tanker trains are only the most visible way that the changing U.S. energy picture is transforming railroads. The fracking revolution has brought other business to railroads, from pipes to propane, and more change is underway.
Read the complete story at the Scientific American.