The First Earth Day in April 1970

It may be hard to imagine that before 1970, a factory could spew black clouds of toxic smoke into the air or dump tons of toxic waste into a nearby stream, and that was perfectly legal. They could not be taken to court to stop it.

https://www.epa.gov/history/epa-history-earth-day#:~:text=In%20spring%201970%2C%20Senator%20Gaylord%20Nelson%20created%20Earth,tackle%20environmental%20issues%2C%20the%20U.S.%20Environmental%20Protection%20Agency.