Over the last 20 years, coalition building has become a prominent intervention employed in communities across America. Coalitions provide community psychologists and those in related fields with a chance to work with whole communities and to better understand how to create community change. As we reflect on the past two decades of community coalition building, there are many questions to be answered about this phenomenon. Why has there been such an upsurge in community coalition building activity? What is the impact of this activity? What have we as students of community learned? What are the questions that we need to be asking to improve the effectiveness of coalition building efforts and their evaluation? This set of articles will review the state of the art of community coalition building in both practice and research. The structure of the articles reflects a collaborative process, with multiple contributors from different disciplines, using a variety of formats. Because this is an evolving phenomenon where the questions asked are as important as the lessons learned, many of the major sections include dialogues with community experts from across the country and from multiple fields, including community psychology, public health, political science, public administration, and grassroots organizing.