In every era in the history of U.S. public policies toward children, certain groups of children have been identified as being "at risk" and hence of social concern and responsibility. These groups consist of the physically handicapped and those with serious diseases; the emotionally disturbed; the mentally retarded; orphans; children whose mothers or fathers are permanently or temporarily absent; illegitimate, destitute, indigent, neglected, abused, and anti-social or delinquent children. Only very recently have the children belonging to specified ethnic, racial, and language groups been added as major "risk" categories and thus become a major focus of social concern and public responsibility. The principal purpose in this monograph is to trace major trends in the evolution of those aspects of social policies toward children that bear directly on issues of ethnic, racial, and language diversity in our society. It also seeks to examine the public attitudes, the intellectual assumptions, and the sociodemographic trends that have accompanied these policy developments. In addition, it pays some attention to the roles that the social and behavioral sciences have played with regard to such policies.