Adolescent pregnancy first emerged as a major social problem in the late 1960s and early 1970s. Among the responses to this problem was the promotion at the national, State, and local levels of an intervention model linking education, social, and health services for pregnant and parenting teenagers. This study addresses: (1) how and why local programs for pregnant and parenting adolescents have been developed and maintained, and (2) what accounts for the development and maintenance of comprehensive programs in some communities and not in others that appear equally or more needy. Four states were selected for study: Massachusetts, Michigan, California, and Tennessee. Within each state a pair of localities were chosen (two in California) making a total of five pairs matched according to socioeconomic and demographic characteristics. Each pair included one locality with a comprehensive program and one without. Programs were evaluated according to the following criteria: (1) leadership, (2) knowledge of alternative program models, (3) State funds, (4) policies and technical assistance, (5) advocacy group and interest group activities, and (6) State and local political culture. After an overview describing the purpose and design of the study, including a definition of the term "comprehensive," State and local case studies are presented for each of the ten localities. Finally, the book addresses the concept and constraints of comprehensive services, discusses conditions and strategies for successful program initiation and maintenance, and offers recommendations. (LHW)