Forty-five years ago today, the United States celebrated Earth Day for the first time. While the country was already seeing increased concern about pollution and general environmental degradation, the rallies taking place on April 22, 1970, helped start the modern environmental protection movement.

Student activists, led by Denis Hayes, helped organize the rallies and events that would take place across the country. Their work most definitely paid off. More than 20 million Americans participated in Earth Day activities in large cities and small towns alike.

The awareness and concern for the environment brought on by public rallies and events helped pass major environmental protection measures in the 1970s, which included the Clean Air Act, Clean Water Act and the Endangered Species Act.

While the environmental issues have evolved since the 1970s, concerns about climate change and other environmental issues makes public awareness and informational campaigns just as important today as they were then.

Looking for ways you can make an impact in protecting the environment? Visit this list of '50 Ways to Help the Planet.'

Learn more:
Meet the Organizers of the Very First Earth Day – Time Magazine
Earth Day Network
Earth Day and garden event calendar – Illinois Times