Who was the national coordinator for the first Earth Day?

Denis Hayes was the national coordinator for the first Earth Day.

Hayes was a Harvard graduate student when he became interested in Senator Gaylord Nelson’s proposal for a national environmental teach-in. Nelson selected him to organize the campaign, and Hayes left Harvard to build a national operation involving regional coordinators, schools, universities, community groups, and volunteers.

The first Earth Day took place on April 22, 1970. Events involved roughly 20 million Americans across about 2,000 colleges and universities, 10,000 primary and secondary schools, and hundreds of communities. Hayes’s decentralized organizing approach helped the campaign spread rapidly across the country.

Hayes later helped make Earth Day international. He organized the 1990 anniversary, when participation expanded to about 200 million people in 141 countries, and he later founded the Earth Day Network. Gaylord Nelson was the movement’s political founder, but Hayes was its national organizer—an important distinction behind this question.