The Erie Canal at wintertime is frustratingly stagnant. It freezes over quickly and remains grimy, not glossy, for months on end, the long history of mules and barges and manpower seemingly frozen in its depths. I once took a trip to the outskirts of Washington, D.C., and saw another historic canal, the C & O Canal. It wasn’t as wide as the Erie, and in the summer heat it looked sulky and morose, the water barely visible at points, with sets of children’s clothes caked in mud and grime on the banks. Pigeons peppered and pecked at whatever they could scavenge. If railroads were once deemed the veins of the American countryside, then canals must have been stem cells, the marrow in the bones of America’s body. And now it looked as if they were being eaten alive.