Low‑concentration fosters faster assimilation

Historical census microdata (1880–1930) show that second‑generation immigrants were more likely to marry outside their group in states where their co‑ethnic concentration was low—for example, higher outmarriage in Wyoming, Oregon, and parts of the Deep South than in immigrant‑dense Northeastern states. Ethnic institutions and dense local ecosystems (churches, newspapers) in high‑concentration areas slowed outmarriage even when groups had similar absolute numbers. — If assimilation depends more on local demographics and institutional density than on national narratives about cities, policymakers should reassess assumptions about integration strategies and the effects of present‑day immigrant clustering.