Every April 22 marks the anniversary of the beginning of the environmental movement in 1970. Inspired by student anti-war protests and concerned by environmental pollution, U.S. Sen. Gaylord Nelson Wisconsin tapped U.S. Rep. Pete McCloskey California to co-chair a movement for teach-ins on college campuses. They enlisted the help of activist Dennis Hayes, to organize the teach-ins. He also formed a national network to promote similar events. The first Earth Day moved 20 million Americans to peacefully protest the environment’s deterioration.