This Saturday April 22 is Earth Day, in fact, it's the 30th anniversary of the first Earth Day. The idea was hatched by Senator Gaylord Nelson of Wisconsin in the late 1960s, when environmental issues weren't really on the political radar screen.

That was a time of unrest on college campuses over the Vietnam War. Anti-war protests, called teach-ins, were being held nationwide. Senator Nelson thought: Why not have a nationwide teach-in about the environment, to force the issue onto the national political agenda? And millions of people turned out for that first Earth Day in spring 1970.

In 1995, Nelson received this nation's highest civilian award - the presidential medal of freedom. He was hailed as the grandfather of all that grew out of that first Earth Day, including the Environmental Protection Act, the Clean Air Act, and the Clean Water Act.