In 1969 at the UNESCO Conference in San Francisco, peace activist John McConnell  proposed a day to honor the Earth and the concept of peace, to first be celebrated on March 21, 1970, the first day of spring in the northern hemisphere. This day of nature's equipoise was later sanctioned in a Proclamation written by McConnell and signed by Secretary General U. Thant at the United Nations. A month later a separate Earth Day was founded by United States Senator Gaylord Nelson as an environmental teach-in first held on April 22, 1970. 
Nelson was later awarded the Presidential Medal of Freedom Award in recognition of his work. While this April 22 Earth Day was focused on the United States, an organization launched by Denis Hayes, who was the original national coordinator in 1970, took it international in 1990 and organized events in 141 nations. Numerous communities celebrate Earth Week, an entire week of activities focused on environmental issues.
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. It also prompted President Bill Clinton to award Senator Nelson the Presidential Medal of Freedom (1995) -- the highest honor given to civilians in the United States - for his role as Earth Day founder.
As the millennium approached, Hayes agreed to spearhead another campaign, this time focused on global warming and a push for clean energy. With 5,000 environmental groups in a record 184 countries reaching out to hundreds of millions of people, Earth Day 2000 combined the big-picture feistiness of the first Earth Day with the international grassroots activism of Earth Day 1990. It used the Internet to organize activists, but also featured a talking drum chain that traveled from village to village in Gabon, Africa, and hundreds of thousands of people gathered on the National Mall in Washington, DC. Earth Day 2000 sent world leaders the loud and clear message that citizens around the world wanted quick and decisive action on clean energy.
Much like 1970, Earth Day 2010 came at a time of great challenge for the environmental community. Climate change deniers, well-funded oil lobbyists, reticent politicians, a disinterested public, and a divided environmental community all contributed to a strong narrative that overshadowed the cause of progress and change. In spite of the challenge, for its 40th anniversary, Earth Day Network reestablished Earth Day as a powerful focal point around which people could demonstrate their commitment. Earth Day Network brought 225,000 people to the National Mall for a Climate Rally, amassed 40 million environmental service actions toward its 2012 goal of A Billion Acts of Green®, launched an international, 1-million tree planting initiative with Avatar director James Cameron and tripled its online base to over 900,000 community members.
The fight for a clean environment continues in a climate of increasing urgency, as the ravages of climate change become more manifest every day. We invite you to be a part of Earth Day and help write many more victories and successes into our history. Discover energy you didn't even know you had. Feel it rumble through the grassroots under your feet and the technology at your fingertips. Channel it into building a clean, healthy, diverse world for generations to come.