Earth Day was first observed on April 22, 1970. The goal of the day was to attract public attention to the growing needs for cleaner air and water. Additionally, the need to conserve the earth's natural resources was emphasized.
Former Senator Gaylord Nelson first proposed the idea for Earth Day in 1969. He came up with the idea while reading about anti-war teach-ins which were occurring on several college campuses in the United States. Nelson's idea was to have a nationwide teach-in on the environment. His idea became very popular and in 1970, more than 20 million people participated in the first Earth Day.
On the 25th anniversary of Earth Day in 1990, more than 200 million people worldwide participated in activities designed by the Earth Day Network to "increase awareness, responsibility and action toward a clean, health future for all living things."