In this age of multicultural democracy, the idea of assimilation seems outdated and, in some forms, even offensive. But as Richard Alba and Victor Nee show in the first systematic treatment of assimilation since the mid-1960s, it continues to shape the immigrant experience. Surveying a variety of domains--language, socioeconomic attachments, residential patterns, and intermarriage--they demonstrate the continuing importance of assimilation in American life.