The first Earth Day, on April 22, 1970, was a milestone event for the planet. An estimated 20 million people took to the streets across the U.S. to raise awareness about the impacts of human activities on the environment.

Since then, the annual tradition has grown to involve billions of people around the world. This year, Earth Day turns 49. To mark this anniversary and to show how much has changed since 1970, we assembled 49 of the most significant accomplishments of the environmental movement since the first Earth Day.

The National Environmental Policy Act of 1969 went into effect the following year, becoming a landmark law that requires every major decision of the federal government to be evaluated for