h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

One city I have visited built much of its twentieth century economy on glass.
Wikipedia says:
Toledo is known as the Glass City because of its long history of innovation in all aspects of the glass industry: windows, bottles, windshields, construction materials, and glass art, which the Toledo Museum of Art has a large collection. Several large glass companies have their origins here. Owens-Illinois, Owens Corning, Libbey Glass, Pilkington North America (formerly Libbey Owens Ford), and Therma-Tru have long been a staple of Toledo's economy. Other off-shoots and spinoffs of these companies also continue to play important roles in Toledo's economy. Fiberglass giant Johns Manville's two plants in the metro area were originally built by a subsidiary of Libbey Owens Ford. Many other companies that service the glass industry also began in Toledo, such as Toledo Engineering and Glasstech.[23][24]