This book examines children's rights and citizenship in the USA, UK and Australia and analyses the policy, law and sociology that govern the transition from childhood to adulthood. By examining existing debates on childhood citizenship, the author pursues the claim that childhood is the most heavily governed period of a liberal individual's life, and argues that childhood is an intensely monitored period that involves a 'politics of becoming adult'. Drawing upon case studies from the USA, the UK and Australia, this concept is used to critically analyse debates and policy concerning children's citizenship, criminality, and sexuality. In doing so, the book seeks to uncover what informs and limits how we think about, talk about, and govern children's rights in liberal societies.