This paper uses decennial Census data to examine the residential integration of the foreign born in the United States between 1910 and 2000. Immigrant segregation declined in the first part of the century, but has been rising over the past few decades. Recent immigrants tend to hail from countries with greater cultural distinctions from U.S. natives, whether economic, racial, or linguistic. These factors explain much of the increase in segregation after 1970. Evidence also points to changes in urban form, particularly native-driven suburbanization and the decline of public transit as a transportation mode, as an explanation for the new immigrant segregation.