Earth Day is celebrated annually on April 22 in more than 191 countries worldwide, with around 1 billion people participating in activities each year. The activities are organized by the Earth Day Network and they focus on the aspects of creating a better Earth, from economic policy makers to saving whales.Founded in 1970 by Gaylord Nelson, Wisconsin Senator at the time, the day was specifically created for the United States, later spreading worldwide.Senator Nelson wanted to put environmental issues and protection on the agenda, so he invented a national teach-in on the environment. He hired Denis Hayes as the national coordinator of events around the US. The day was a big success in the US, with the Clean Air and Clean Water Act as some of the many positive outcomes.In 1990, Hayes was approached again by international environmental group leaders to organize another Earth Day, this time internationally. Various events were organized in 141 countries all over the world to raise awareness and to put environmental issues on the international political agenda.