Immigrants and the Making of America. Nathan Nunn, September 13, 2018, Paper, “We study the effects of European immigration to the United States during the Age of Mass Migration (1850–1920) on economic prosperity. Exploit cross-county variation in immigration arising from the interaction of fluctuations in aggregate immigrant flows and the gradual expansion of the railway network, we find that counties with more historical immigration have higher incomes, less poverty, less unemployment, higher rates of urbanization, and greater educational attainment today. The long-run effects seem to capture the persistence of short-run benefits, including greater industrialization, increased agricultural productivity, and more innovation.Link