A little background on Earth Day and Earth Week.
The first Earth Day was April 22, 1970 and was instigated by Gaylord Nelson, a Senator from Wisconsin after taking a trip to Santa Barbara and viewing the terrible aftermath of the oil spill off the coast in 1969. The first Earth Day led to the creation of the United States Environmental Protection Agency and the passage of the Clean Air, Clean Water, and Endangered Species Acts.
Earth Day 1970 in Philadelphia gave birth to Earth Week, April 16–22. It was created by a committee of students, professionals and leaders of grass roots organizations and businessmen concerned about the environment and inspired by Senator Gaylord Nelson’s call for a national environmental teach-in.
In 1990, a group of environmental leaders asked Denis Hayes to organize another big campaign. This time, Earth Day went global, mobilizing 200 million people in 141 countries and lifting environmental issues onto the world stage. Earth Day 1990 gave a huge boost to recycling efforts worldwide and helped pave the way for the 1992 United Nations Earth Summit in Rio de Janeiro.
And…that is how the movement started in 1970.