On the very first Earth Day in 1970, Denis Hayes stood on a stage in Central Park, stunned by the number of people who'd come to honor the planet. Now 76 years old, Hayes remembers it was like looking at the ocean—“you couldn’t see where the sea of people ended.” Crowd estimates reached more than a million people.
For Hayes, who is now board chair of the international Earth Day Network, it was the culmination of a year’s worth of work. As an urban ecology graduate student at Harvard University, he’d volunteered to help organize a small initiative by Wisconsin senator Gaylord Nelson. Nelson was horrified by the 1969 oil spill in Santa Barbara, California, and wanted to raise awareness about environmental issues by holding teaching events similar to those being held by civil rights and anti-war activists.
Senator Nelson saw a growing disconnect between the concept of progress and the idea of American well-being, Hayes tells mental_floss. “There was a sense that America was prosperous and getting better, but at the same time, the air in the country was similar to the air today in China, Mexico City, or New Delhi," Hayes says. "Rivers were catching on fire. Lakes were unswimmable.”
Hayes talked to mental_floss about the process that led to the first Earth Day, and how the movement took off afterward and grew into a global initiative.