We've been celebrating Earth Day for 50 years now, but even the most ardent activists of today would have a hard time picturing the intensity and excitement that the first Earth Day in 1970 brought. Before the first Earth Day, no one used the phrase "environmental movement". But that first Earth Day - conceived by Gaylord Nelson as a teach-in - sparked an unprecedented conversation about pollution, wilderness protection, sprawl, and more.

Join Adam Rome, professor of Environment and Sustainability at the University of Buffalo, as he uncovers the motivation for, and the lasting impact of, a national day devoted to environmental awareness. Discover how the "Green Generation" was conceived by young Americans who had been encouraged to think they could change the world in the 1960s and who were frustrated that the adults of their generation were not addressing pressing ecological issues.

While current Earth Day celebrations remind us to "go green", recycle and reuse, and offset our carbon footprints, explore how the original Earth Day had much wider ramifications. Its legacy includes the creation of the Environmental Protection Agency and the passage of the Clean Air Act. It also inspired a new generation of entrepreneurial activists who started environmental organizations, became green architects or lawyers, launched eco businesses, and much more.

The story of Earth Day offers practical lessons about ways to continue moving forward. But most important, it offers inspiration about how one person can start a movement that changes the world.