As the country began to prosper in the '90s, the city of Potosi, Mo., languished in Depression-era unemployment. Until recently, that is, when the manufacturing plants that have tended to go elsewhere began to return.

It was only a decade or so ago that the Evansville, Ind., economy was in a slump. These days, though, it's the darling of the state. How did the turnaround come about?