Since the first Earth Day in 1970, the United States and nations around the world have made significant progress in protecting the environment.
However, there is much work to be done, and new challenges have emerged. In this timeline, we examine the progress—and the setbacks—over the past 50 years.
1970: First Earth Day
On April 22, an estimated 20 million people march in U.S. streets to call attention to the urgent need for environmental protections.
