This article presents an overview of the Hispanic population of the United States, focusing on the sources of its growth, its internal composition, its connections with the countries of origin, its role in the U.S. economy, and the emerging second generation. Intergenerational differences in outlooks and self-identities and the forces leading to the emergence of a “thick” Hispanic identity in the second generation are examined. The obstacles to successful integration faced by this youthful population and evidence of both “upward” and “downward” assimilation among its members are analyzed. Implications for the field of race and ethnic relations and for public policy toward immigrants and their offspring are discussed.