This paper analyzes geographic patterns of population concentration and deconcentration among the foreign-born population during the 1990-2000 period. A goal is to examine whether the foreign-born population, including recent arrivals, are dispersing geographically from metro gateway cities into rural and other less densely populated parts of the country. The paper also evaluates the so-called balkanization hypothesis, which is that immigration flows run counter-cyclical to the redistribution trends of the native-born population, while reinforcing spatial isolation and immigrant segregation. Data for U.S. counties or county equivalents come from the 1990 and 2000 U.S. Census (Summary Files 1, 3 and 4). Our results suggest that America's immigrant population is dispersing spatially. Immigrants are less concentrated today than in the past and they are less segregated from other population groups, including their own racial group and whites. However, changes over the past decade have been modest. The immigrant population, even in 2000, remained considerably more concentrated than the native-born population. The empirical results provide little evidence of geographic balkanization. (Contains 3 figures, 6 tables, and 7 footnotes.)