About 1.4 million people emigrated from Sweden to America 1860-1920 from which approximately 200,000 returned. Many returnees had been exposed to new ideas and technologies. Coupled with capital and acquired skills, these ideas could be brought back and implemented at home. At the same time, Sweden went from being a poor country in the European periphery to one of the fastest growing economies. What was the role of returnees in this phase of modernization? In particular, this project asks the overarching question “How did returnees from the Great emigration contribute to Swedish entrepreneurship?” Of course, not all regions benefited from returning migrants. Quite surprisingly, systematic knowledge about regional resettlement patterns and subsequent effects on entrepreneurial activities is largely lacking. Such patterns may have more bearing on our understanding of present-day entrepreneurship than we think. The literature shows that entrepreneurial and inventive behavior is not only highly unequally distributed in geographical space, but also extremely regionally persistent (Reynolds et al., 1994, Fritsch and Storey, 2014). This means that, given their numbers, returnees may have changed both the regional distribution and the type of entrepreneurship that we observe, even today. This project addresses these phenomena by asking three questions: a) “Which regions benefitted from returnee entrepreneurship?“, b) “Did the effect of returnee entrepreneurship generate persistent local effects?” and c) Through which mechanisms were these effects transmitted?