The environmental movement encompasses many issues, including pollution, conservation, climate change, and alternative energy. Environmentalists maintain that people are part of ecosystems and must act to keep those systems balanced and healthy. This compelling guide to the history of the movement, including efforts today, focuses on important environmental crusaders, including Rachel Carson and John Muir, and the organizations that have fought for world-changing legislation. Historical photographs and a timeline help shed light on principal events in this on-going movement.