This paper reanalyzes data from the Gluecks classic study of 500 delinquents and 500 nondelinquents reared in low-income neighborhoods of central Boston. Based on a general theory of informal social control, we propose a 2-step hypothesis that links structure and process: family poverty inhibits family processes of informal social control, in turn increasing the likelihood of juvenile delinquency. The results support the theory by showing that (1) erratic, threatening, and harsh discipline, (2) low supervision, and (3) weak parent-child attachment mediate the effects of poverty and other structural factors on delinquency. We also address the potential confounding role of parental and childhood disposition. Although difficult children who display early antisocial tendencies do disrupt family management, as do antisocial and unstable parents, mediating processes of informal social control still explain a large share of variance in adolescent delinquency. Overall, the results underscore the indirect effects of structural contexts like family poverty on adolescent delinquency within disadvantaged populations. We note implications for current debates on race, crime, and the "underclass" in urban America.