Answer: Clean Air Act
Step-by-step explanation:
Although Earth Day was only officially recognized in 1970, it was influencing activities years before that. As people began to see the disastrous effects of pollution on the environment, action had to be taken especially after the popularity of the book, Silent Spring.
Passed in 1963, the Clean Air Act showed that the Federal government was getting alarmed at the increase in air pollution and so established rules aimed at mitigating it. The Act has been hailed as one of the most comprehensive in the world and explains why the United States with all its industry, does not see the smog that Beijing does.