People made major statements at the first Earth Day, protesting the state of the environment with gas masks.

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Earth Day 1970

­In 1970, protesting was practically a way of life in the United States. Young people and Hollywood stars, many of whom had been protesting the Vietnam War for years, took to Earth Day like fish to water. Back then, Earth Day wasn't the sedate celebration it is now. Some misguided young people actually smashed car windows for the cause, and many people walked the streets wearing gas masks.

But even those who weren't avid tree-hugging protesters showed up for that first Earth Day. Mainstream America got involved, too, after major newspapers started covering pollution-related health hazards on their front pages in preparation for the event.

At the time of Earth Day 1970, and the early years in general, it was the "conservation" movement, not the "environmental" movement. The focus was on preserving and protecting. Issues like air and water pollution, deforestation, nuclear testing and paving over parks were the big ones -- global warming wasn't yet on the docket.

Earth Day 1970 had a turnout few people expected. Around the United States and into Canada, 20 million people showed up at Earth Day rallies to draw attention to the cause and make the government take notice. It was a stunning success, especially considering the organizers' meager budget. With just $200,000, the Earth Day Network managed to set up rallies, speakers and teach-ins in places like Washington, D.C., New York City and Portland, all centered on the idea that people had to rethink their relationship with the Earth or suffer the consequences [source: Lewis].

Those early Earth Days were a measurable success, something that's pretty rare for a volunteer-driven protest. In December 1970, within seven months of the first Earth Day, the U.S. Environmental Protection Agency (EPA) was born. The Clean Air Act was broadened in 1970 and 1977, and the Endangered Species Act was passed in 1973. In 1980, Congress established Superfund to clean up hazardous waste sites. It was an incredible decade for environmental progress, and Earth Day 1970 played a big part in getting the ball rolling.

It's hard to replicate the excitement of the start of a movement that actually makes a difference. These days, Earth Day is less about protest and more about working toward particular goals.

It's also much, much bigger.