In 2006, Tom Chappell sold most of the company he founded—Tom’s of Maine, a pioneer in the field of natural toothpastes, deodorants and other personal care products—for a cool $100,000,000. It wasn’t long before he started thinking about his next business venture. “I didn’t want to join a lot of boards of directors and play a lot of golf,” he says, “and I wanted to be useful.”

In less than three years Chappell had started another company, a maker of men’s and women’s clothing called Ramblers Way. Going into textiles and the garment industry was a big commitment, more of a commitment than he thought, and the challenges were especially formidable because Chappell wanted, as much as possible, to manufacture clothes in the U.S.A. with an emphasis on sustainability.

Ramblers Way clothes are made from high-quality wool and cotton, and employees’ faces light up when talking about the virtues of wool. For one thing, it doesn’t absorb odors, which means it doesn’t have to be cleaned nearly as often as other fabrics. Thus, greater sustainability. “For all the innovations that are coming along,” says supply chain manager Nick Armentrout, “you really can’t beat what wool does without too much help from man.”

Ramblers Way was set to open its fourth retail store on Thursday. It’s located in Portland’s Old Port, and it will be followed, if all goes according to plan, by about twenty more stores in cities around the country over the next four or five years. For Tom Chappell, who doesn’t need the headaches or the money that come with running a new business, it is not a sideline. “This,” he says with a chuckle, “is all in.”