Earth Day began in the United States. In 1969, U.S. Senator Gaylord A. Nelson said we should have a day of environmental education be held on college campus. The next year, the lawyer and environmentalist Denis Hayes, who graduated from Stanford, led hundreds of students in planning and organizing the first Earth Day. About 20 million people participated in the original celebration on April 22, 1970.
The first Earth Day in 1970 helped tell people about the threat of pollution and started a new environmental movement. That same year, Congress created the Environmental protection Agency to set and enforce pollution standards. Congress also passed the Clean Air Act of 1970, which limited the amount of air pollution that cars, utilities, and industries could release. Other new environmental laws soon followed.