Grassroots activism is essential to the success of the contemporary environmental movement, which depends on the organization of local activists as well as state, national, and international organizations. Yet grassroots activists confront numerous challenges as they attempt to organize diverse participants and devise fresh strategies and tactics. Drawing on more than seven years of fieldwork following diverse organizations in Pittsburgh over time, this book sheds light on the struggles that activists face and the factors that sustain movements. Suzanne Staggenborg examines individual motivations and participation, organizational structures and cultures, relationships in movement communities, and strategies and tactics, including issue framing. The book shows that collective action campaigns and tactics generate solidarity, maintain involvement, and bring in new participants even as organizers struggle to devise effective new types of actions.