Why did Gaylord Nelson and Denis Hayes organize the first Earth Day in 1970?

In the late 1960s, U.S. Senator Gaylord Nelson sought to revitalize the conservation movement by creating a national event that would elevate environmental protection to the forefront of the national political agenda.1

To achieve this, Nelson recruited Denis Hayes, a Harvard graduate student, to help organize the initiative. Their primary strategy was to harness the energy and momentum of student-led anti-war activism and merge it with the public's growing environmental consciousness.1

By designing the first Earth Day in 1970 as an "environmental teach-in," they aimed to educate the public on the importance of ecological sustainability and conservation. This effort was highly successful, drawing 20 million participants and serving as a catalyst for significant legislative achievements in the 1970s, including the Clean Air Act and the Endangered Species Act.1