This article focuses on settlement trends of immigrants during the periods that bookend the twentieth century, both eras of mass migration. It compares settlement patterns in both periods, describing old and new gateways, the growth of the immigrant population, and geographic concentration and dispersion. Historically, immigrants have been highly concentrated in a few places. Between 1930 and 1990, more than half of all immigrants lived in just five metropolitan areas. Since then, the share of these few destinations has declined, as immigrants have made their way to new metro areas, particularly in the South and West. During the same period, immigrants began to choose the suburbs over cities, following the decentralization of jobs and the movement of opportunities to suburban areas. There are now more immigrants in U.S. suburban areas than cities.