The first Earth Day was held on April 22, 1970, and featured a series of teach-ins, rallies and protests across the the United States

The goal was to raise awareness about pollution, waste and the need for environmental conservation.

Earth Day directly contributed to creation of the U.S. Environmental Protection Agency and passage of the Clear Air, Clean Water and Endangered Species acts.

It is celebrated annually on April 22.

Earth Day became a global event in 1990, with 200 million people from 141 countries participating.

Today, about 1 billion people from more than 190 countries participate in Earth Day activities.