John Kingdon is an American political scientist best known for his work on public policy and agenda-setting. He is particularly recognized for his book, "Agendas, Alternatives, and Public Policies," published in 1984, which explores how issues gain attention in the political arena. Kingdon introduced the concept of the "policy stream," which describes how problems, solutions, and political circumstances converge to create opportunities for policy change. Kingdon's work has significantly influenced the field of public policy analysis and has been widely cited in academic literature. His theories help explain how certain issues become prioritized by policymakers and how various factors, including public opinion and political will, shape the policy-making process.