Earth Day is an annual holiday celebrated on the 22nd of April every year. The first time Earth Day was celebrated was in 1970 with over 20 million people in attendance across the United States. The date was chosen because it was in between college spring breaks and Arbor Day.  It was a day where people of different groups fighting for different issues surrounding the Earth, to come together and celebrate the Earth and bring awareness to these issues.

The event was created by Senator Gaylord Nelson and with the help of Harvard graduate student Denis Hayes. The event strengthened the support for legislation such as The Clean Air Act and Endangered Species Act. In December of 1970, Congress approved the creation of a new federal agency for environmental issues; U.S. Environmental Protection Agency.

In 1990, Hayes arranged a global Earth Day, with more than 200 million participants in 140 or more countries. Earth Day now brings in more than 200,000 partners and organizations from 190 countries that support the Earth in a year long mission. This event brings together over 1 billion people, making it one of the largest public events in the world.