Pablo Diaz, executive director of the Grenada County Economic Development District in Grenada, Miss., proudly calculates that about 30 percent of local jobs are in manufacturing. That's astonishing at a time when that slumping sector accounts for less than 9 percent of jobs nationally, according to the Bureau of Labor Statistics.

Grenada's manufacturing prowess can be chalked up chiefly to the staying power of a single enterprise established in town in the mid-1950s. A Minnesota company, attracted by the South's relatively low production costs, hired a handful of employees to make coils for heating, ventilating and air-conditioning applications.

Coils consist of tubing (typically copper) sandwiched in metal (typically aluminum). Over the years, they have come in ever more sizes and shapes for ever more residential, commercial and industrial temperature-control uses. Grenada (pronounced gre-NAY-dah) is fortunate today in having landed an early piece of what became a growth industry.