For several decades, Mexican immigrants in the United States have outnumbered those from any other country. Though the economy increasingly needs their labor, many remain unauthorized. In Parents Without Papers, immigration scholars Frank D. Bean, Susan K. Brown, and James D. Bachmeier document the extent to which the outsider status of these newcomers inflicts multiple hardships on their children and grandchildren. Parents Without Papers provides both a general conceptualization of immigrant integration and an in-depth examination of the Mexican American case. The authors draw upon unique retrospective data to shed light on three generations of integration. They show in particular that the “membership exclusion” experienced by unauthorized Mexican immigrants—that is, their fear of deportation, lack of civil rights, and poor access to good jobs—hinders the education of their children, even those who are U.S.-born. Moreover, they find that children are hampered not by the unauthorized entry of parents itself but rather by the long-term inability of parents, especially mothers, to acquire green cards. When unauthorized parents attain legal status, the disadvantages of the second generation begin to disappear. These second-generation men and women achieve schooling on par with those whose parents come legally. By the third generation, socioeconomic levels for women equal or surpass those of native white women. But men reach parity only through greater labor-force participation and longer working hours, results consistent with the idea that their integration is delayed by working-class imperatives to support their families rather than attend college. An innovative analysis of the transmission of advantage and disadvantage among Mexican Americans, Parents Without Papers presents a powerful case for immigration policy reforms that provide not only realistic levels of legal less-skilled migration but also attainable pathways to legalization. Such measures, combined with affordable access to college, are more important than ever for the integration of vulnerable Mexican immigrants and their descendants.