Judged by how long it has been going on, the current U.S. economic expansion should be on its last legs, but the mood in this rebounding heartland auto town would not show it. Fiat Chrysler Automobiles (FCAU.N) (FCHA.MI) has doubled its local workforce to 7,000 amid record industry sales, upscale apartments are being built or tucked into vacant factories, and new small businesses are opening along a quaint Main Street. As the Federal Reserve meets to begin a likely turn towards higher interest rates, the buzz in places such as Kokomo is one reason policymakers think the U.S.