WASHINGTON, D.C. --- Sunday's 2009 Earth Day celebration on the National Mall launched "The Green Generation" campaign -- a nationwide effort to encourage renewable energy, green jobs and a new green economy. 

With music by the Flaming Lips, moe., Los Lobos and others, the free event was the flagship in a coordinated country-wide Earth Day Weekend of environmental volunteer actions and music in Washington D.C., New York, Boston, Atlanta, Chicago, Denver, Austin, Los Angeles, San Francisco and Seattle. 

Attended by over 200,000 last year, the Green Apple-Earth Day Festival has grown from eight cities to 10 cities in 2009. 

Across the U.S. on Earth Day Weekend, Green Apple volunteer projects in parks, beaches, schools and forests focused on climate change solutions like tree planting, energy efficiency retrofits, water protection, urban gardens and forest restoration. 

The beginnings of Earth Day can be traced back to a conference in Seattle in September 1969, when Senator Gaylord Nelson of Wisconsin announced that in the spring of 1970 there would be a nationwide grassroots demonstration on behalf of the environment.

"The wire services carried the story from coast to coast," Nelson recalled later. "The response was electric. It took off like gangbusters. Telegrams, letters, and telephone inquiries poured in from all across the country. The American people finally had a forum to express its concern about what was happening to the land, rivers, lakes, and air -- and they did so with spectacular exuberance." 

Five months before that first Earth Day, on Sunday, November 30, 1969, the New York Times carried a lengthy article on the proliferation of environmental events:

"Rising concern about the environmental crisis is sweeping the nation's campuses with an intensity that may be on its way to eclipsing student discontent over the war in Vietnam...a national day of observance of environmental problems...is being planned for next spring...when a nationwide environmental 'teach-in'...coordinated from the office of Senator Gaylord Nelson is planned...."

"Earth Day worked because of the spontaneous response at the grassroots level," Sen. Nelson explained in an article he wrote in 1993. "We had neither the time nor resources to organize 20 million demonstrators and the thousands of schools and local communities that participated. That was the remarkable thing about Earth Day. It organized itself." 

An estimated 20 million Americans participated in the first Earth Day. Each year since, Earth Day has been observed around the world.

When Sen. Nelson received the Presidential Medal of Freedom in 1995, President Clinton noted, "As the founder of Earth Day, he is the grandfather of all that grew out of that event -- the Environmental Protection Act, the Clean Air Act, the Clean Water Act, the Safe Drinking Water Act. He also set a standard for people in public service to care about the environment and try to do something about it."  

Sen. Nelson died on July 3, 2005, at his home in Bethesda, MD, at the age of 89. 

Earth Day 2009 events are a kick-off to the 40th Anniversary of Earth Day, which will culminate in April 2010 with Global Days of Service on April 17-18, 2010 and a Global Day of Action on April 22, 2010 -- the 40th anniversary of Earth Day -- when participants will ask their governments to take specific environmental action. 

This will be followed by a Global Day of Celebration on April 25th, 2010 -- a day that will feature 40 simultaneous music and rally events across the world focused on the theme of "The Green Generation." 

Earth Day Network was "founded on the premise that all people, regardless of race, gender, income or geography, have a moral right to a healthy, sustainable environment," the group said. "Our mission is to broaden and diversify the environmental movement worldwide, and to mobilize it as the most effective vehicle for promoting a healthy, sustainable environment." 

Earth Day Network has a global reach with a network of more than 17,000 partners and organizations in 174 countries.  More than 1 billion people participate in Earth Day activities. 

Now in its fourth year, the Green Apple Festival began in New York City as an environmental and music event and has grown to become the country's largest coordinated and interactive festival dedicated to observing and preserving the environment.