The Rosetans began buying land on a rocky hillside, connected to Bangor only by a steep, rutted wagon path. They built closely clustered two story stone houses, with slate roofs, on narrow streets running up and down the hillside. They built a church and called it Our Lady of Mount Carmel, and named the main street on which it stood Garibaldi Avenue, after the great hero of Italian unification. In the beginning, they called their town New Italy. But they soon changed it to something that seemed more appropriate, given that in the previous decade almost all of them had come from the same village in Italy. They called it Roseto.

In 1896, a dynamic young priest — Father Pasquale de Nisco — took over at Our Lady of Mount Carmel. De Nisco set up spiritual societies and organized festivals. He encouraged the townsfolk to clear the land, and plant onions, beans, potatoes, melons and fruit trees in the long backyards behind their houses. He gave out seeds and bulbs. The town came to life. The Rosetans began raising pigs in their backyard, and growing grapes for homemade wine. Schools, a park, a convent and a cemetery were built. Small shops and bakeries and restaurants and bars opened along Garibaldi Avenue. More than a dozen factories sprang up, making blouses for the garment trade. Neighboring Bangor was largely Welsh and English, and the next town over was overwhelmingly German, which meant — given the fractious relationships between the English and Germans and Italians, in those years — that Roseto stayed strictly for Rosetans: if you wandered up and down the streets of Roseto in Pennsylvania, in the first few decades after 1900, you would have heard only Italian spoken, and not just any Italian but the precise southern, Foggian dialect spoken back in the Italian Roseto. Roseto Pennsylvania was its own tiny, self-sufficient world — all but unknown by the society around it — and may well have remained so but for a man named Stewart Wolf.

Wolf was a physician. He studied digestion and the stomach, and taught in the medical school at the University of Oklahoma. He spent summers at a farm he'd bought in Pennsylvania. His house was not far from Roseto — but that, of course, didn't mean much since Roseto was so much in its own world that you could live one town over and never know much about it. "One of the times when we were up there for the summer — this would have been in the late 1950's, I was invited to give a talk at the local medical society," Wolf said, years later, in an interview. "After the talk was over, one of the local doctors invited me to have a beer. And while we were having a drink he said, 'You know, I've been practicing for seventeen years. I get patients from all over, and I rarely find anyone from Roseto under the age of sixty-five with heart disease.'"

Wolf was skeptical. This was the 1950's, years before the advent of cholesterol lowering drugs, and aggressive prevention of heart disease. Heart attacks were an epidemic in the United States. They were the leading cause of death in men under the age of sixty-five. It was impossible to be a doctor, common sense said, and not see heart disease. But Wolf was also a man of deep curiosity. If somebody said that there were no heart attacks in Roseto, he wanted to find out whether that was true.

Wolf approached the mayor of Roseto and told him that his town represented a medical mystery. He enlisted the support of some of his students and colleagues from Oklahoma. They pored over the death certificates from residents of the town, going back as many years as they could. They analyzed physicians' records. They took medical histories, and constructed family genealogies. "We got busy," Wolf said. "We decided to do a preliminary study. We started in 1961. The mayor said — all my sisters are going to help you. He had four sisters. He said, 'You can have the town council room.' I said, 'Where are you going to have council meetings?' He said, 'Well, we'll postpone them for a while.' The ladies would bring us lunch. We had little booths, where we could take blood, do EKGs. We were there for four weeks. Then I talked with the authorities. They gave us the school for the summer. We invited the entire population of Roseto to be tested."