On the first Earth Day 50 years ago in 1970, an estimated 20 million people across the United States took to the streets on behalf of the environment. Spurred by the mass mobilization, within five years Congress had created some of the most consequential environmental legislation to date: the establishment of Environmental Protection Agency (1970), the Clean Air Act (1970), the Clean Water Act (1972), the Marine Mammal Protection Act (1972), and the Safe Drinking Water Act (1974).

Since that early push, momentum behind environmental conservation has ebbed and flowed, but each year has brought environmental wins—both locally and globally.

We’ve assembled 50 environmental accomplishments—one to celebrate every year since the first Earth Day—to reflect on progress made and ground left to cover.

To mark this year’s anniversary, we highlighted the youth-led climate movement spearheaded by 17-year-old Greta Thunberg and other young leaders around the world. Thunberg has spotlighted a global movement led by young people, but it was well in motion before she came on the scene. (Read about other young activists fighting to save our world.)