ST. LOUIS — It took Beriz Nukic about two years after landing on a new continent as a war refugee to open his own business.

Mr. Nukic learned English on the fly, and started with a simple concept — a Turkish coffee roastery for Bosnians, who drink Turkish coffee as though it is water. Soon he expanded the business into a deli, and then opened a restaurant, Berix, working 18-hour days and carrying a Bosnian-to-English dictionary in his pocket.

He did all that in Bevo Mill, a once-dilapidated neighborhood in the southern part of St. Louis that quickly became the stuff of American dreams. Where boarded-up windows had lined the streets and city development initiatives had never seemed to get off the ground, thousands of refugees fleeing brutal ethnic cleansing half a world away arrived in the 1990s with business plans and home renovations. They learned English, opened cafes and hair salons, and before long had brought life, color and the smell of fresh-baked bread to the area, which came to be known as Little Bosnia.

Amer Iriskic, 28, remembered moving to the neighborhood as a 7-year-old in 1998, three years after the end of the bloody civil war in Bosnia and Herzegovina. “People were outside all the time, and it was a nice atmosphere,” he said. He and his friends played basketball in the alley behind their house. His father and uncle opened a butcher shop, where they sold the cuts of lamb and veal their Bosnian customers missed and that other residents began to love as well.