Research on the development of citizenship is enjoying a renaissance, fueled in part by those who argue that we face a civic crisis today in terms of young people's civic disengagement. Other commentators assert that civic participation has not declined but has simply changed in nature. For instance, youth voting is low but volunteerism is at an all-time high. This debate has sparked public interest and spurred new research. A multidisciplinary field by nature, this special issue of applied developmental science consists of three sections. Section one addresses the concept and definition of citizenship. Section two explores the relationship between communities and their young people. It examines the contributors to youth's entry into citizenship as adults while drawing connections between research and practice. A final section examines four understudied populations: disadvantaged urban youth, ethnic minority youth, immigrant youth, and sexual minority youth. A final chapter by the editors draws out implications for research, education, and programs.