Alejandro Portes and Alejandro Rivas examine how young immigrants are adapting to life in the United States. They begin by noting the existence of two distinct pan-ethnic populations: Asian Americans, who tend to be the offspring of high-human-capital migrants, and Hispanics, many of whose parents are manual workers. Vast differences in each, both in human capital origins and in their reception in the United States, mean large disparities in resources available to the families and ethnic communities raising the new generation. Research on the assimilation of these children falls into two theoretical perspectives. Culturalist researchers emphasize the newcomers' place in the cultural and linguistic life of the host society; structuralists, their place in the socioeconomic hierarchy. Within each camp, views range from darkly pessimistic-that disadvantaged children of immigrants are simply not joining the American mainstream--to optimistic--that assimilation is taking place today just as it has in the past. A middle ground is that although poorly endowed immigrant families face distinct barriers to upward mobility, their children can overcome these obstacles through learning the language and culture of the host society while preserving their home country language, values, and customs. Empirical work shows that immigrants make much progress, on average, from the first to the second generation, both culturally and socioeconomically. The overall advancement of the immigrant population, however, is largely driven by the good performance and outcomes of youths from professional immigrant families, positively received in America. For immigrants at the other end of the spectrum, average socioeconomic outcomes are driven down by the poorer educational and economic performance of children from unskilled migrant families, who are often handicapped further by an unauthorized or insecure legal status. Racial stereotypes produce a positive self-identity for white and Asian students but a negative one for blacks and Latinos, and racialized self-perceptions among Mexican American students endure into the third and fourth generations. From a policy viewpoint, these children must be the population of greatest concern. The authors cite two important policy measures for immigrant youth. One is to legalize unauthorized migrants lest, barred from conventional mobility channels, they turn to unorthodox means of self-affirmation and survival. The other is to provide volunteer programs and other forms of outside assistance to guide the most disadvantaged members of this population and help them stay in school.