People predicting a manufacturing renaissance in the United States usually imagine whirring robots or advanced factories turning out wind turbines and solar panels. The real American edge might be in something entirely more mundane: cheap starting materials for plastic bottles and plastic bags.

The plummeting price of natural gas—which can be used to make a vast number of products, including tires, carpet, antifreeze, lubricants, cloth, and many types of plastic—is luring key industries to the United States. Just five years ago, natural-gas prices were so high that some chemical manufacturers were shutting down U.S. operations. Now the ability to access natural gas trapped in shale rock formations, using technologies such as hydraulic fracturing and horizontal drilling, has lowered American prices to a fraction of those in other countries (see “King Natural Gas”).