Who is credited with founding Earth Day in 1970?

Gaylord Nelson is credited with founding Earth Day in 1970. The Wisconsin senator and former governor had spent years trying to make environmental protection a major political issue. Pollution crises, Rachel Carson’s 1962 book Silent Spring, the 1968 Earthrise photograph, and the 1969 Santa Barbara oil spill helped create the moment for a national campaign.

Nelson proposed an environmental teach-in modeled partly on the campus protests of the 1960s. He recruited Harvard graduate student Denis Hayes to coordinate the nationwide event, while many other activists, schools, unions, and community groups helped organize it. That distinction explains a common mix-up: Nelson is generally called Earth Day’s founder, while Hayes is credited as the first event’s national coordinator and later helped make Earth Day international.

The first Earth Day took place on April 22, 1970. An estimated 20 million Americans participated, and the movement helped build momentum for major U.S. environmental measures, including the creation of the Environmental Protection Agency later that year. Nelson received the Presidential Medal of Freedom in 1995 for his environmental work.