The first Earth Day, April 22, 1970, was initiated by Gaylord Nelson, who was a U.S. senator from Wisconsin and is sometimes called the "father of Earth Day." Nelson's objective was to organize a nationwide public demonstration so large that it would get the attention of politicians and force issues of environmental protection into the legislative forefront. The first Earth Day, coordinated by Harvard Law student Denis Hayes, was celebrated by more than 20 million individuals. That Earth Day is credited with spearheading the modern environmental movement.
Soon after the celebration of the first Earth Day, the following actions were taken by the U.S. government: the establishment of the Environmental Protection Agency (EPA); the creation of the President's Council on Environmental Quality; and the passage of the Clean Air Act, which established national air quality standards.