There was never a guarantee that Detroit would become the Motor City. At the turn of the 20th century, any number of American municipalities with similar access to talent, materials, investment, and transportation might have emerged as the beating heart of the automobile industry. But Detroit prevailed in large part because a handful of companies within the auto manufacturing community served as “tentpoles,” firms so powerful and successful that they anchored an entire economic ecosystem. If, in the early 1900s, you wanted to sell to the range of automotive company that would eventually coalesce into the Big Three, it behooved you to set up shop near Detroit. And for decades, until the entire industry was disrupted, that attraction established a virtuous cycle. GM, Ford, and Chrysler benefitted from the broader network around them as much as members of the network benefitted from being proximate to the nation’s automobile behemoths. And the city of Detroit benefited from being home to a major industry cluster.