In 1926, an Oklahoma oilman named Cyrus Avery maneuvered a federal highway through his hometown of Tulsa — a road nobody wanted the number for. Route 66 became the most famous highway in America, carrying Dust Bowl refugees to California, generating a billion-dollar roadside economy of motels and diners, and inspiring Steinbeck, Nat King Cole, and a generation of postwar travelers. Then the interstate system bypassed it, town by town, draining the commerce from main streets that had depended on through-traffic for decades. This is the story of the deals, the builders, the dollar figures, and the small-town business owners who watched the greatest road in American history rise and fall in a single lifetime.