Each year on Earth day, April 22, marks the anniversary of the birth of the modern environmental movement in 1970. War was raging in Vietnam and students all over the nation overwhelmingly opposed it. At the time, Americans were using leaded gas, and industries let smoke and sludge out into the atmosphere, with little to no fear of legal consequences or bad press. Air pollution was commonly accepted as the smell of “prosperity.” The word “environment” was only heard in spelling bees instead of on the daily news. The stage had been set for changes to be made by the publication of Rachel Carson’s New York Times bestseller Silent Spring in 1962, although mainstream America was basically oblivious to any environmental concerns. More than 500,000 copies of the book were sold in 24 countries, and represented a watershed moment which began to raise public concern and awareness for living organisms, the environment, as well as links between public health and pollution. Earth Day 1970 gave a voice to the public’s emerging consciousness, which channeled the energy of the anti-war protest movement and putting environmental concerns on the front page. The idea for a national awareness day to focus on the environment was first thought of by Gaylord Nelson, a U.S. Senator from Wisconsin, after witnessing the devastation of the massive oil spill in Santa Barbara, California, in 1969. Inspired by the student anti-war movement, he wanted to infuse that energy with an emerging public consciousness about water and air pollution, which would force environmental protection onto the national political agenda. Senator Nelson announced the idea for a “national teach-in on the environment” to the national media, persuaded Pete McCloskey, a conservation-minded Republican Congressman, to serve as his co-chair, and recruited Denis Hayes from Harvard as the national coordinator. Hayes built an 85-person national staff to promote events across the country. The day of April 22, falling between spring break and final exams, was selected as the date for Earth Day. On April 22, 1970, twenty million Americans took to streets, parks, and auditoriums to demonstrate for a healthy, sustainable environment in rallies from coast to coast. Protests against the deterioration of the environment were put together by thousands of colleges and universities around the country. Groups that fought against things such as oil spills, polluting factories and power plants, raw sewage, toxic dumps, pesticides, freeways, the loss of wilderness, and the extinction of wildlife had suddenly realized that they shared common values. Earth Day 1970 achieved a rare political alignment, enlisting support from both Democrats and Republicans, rich and poor, city slickers and farmers, and tycoons and labor leaders. The first Earth Day led to the creation of the United States Environmental Protection Agency and the passage of the Clean Air, Clear Water, and Endangered Species Acts by the end of that year. As 1990 approached, a group of environmental leaders asked Denis Hayes to organize another big campaign. This time, Earth Day turned into a global observance which mobilized 200 million people in 141 countries, and lifted environmental issues onto the world stage. Earth Day 1990 significantly boosted recycling efforts worldwide and helped pave the way for the United Nations Earth Summit in Rio de Janeiro in 1992. It also prompted President Bill Clinton to award Senator Nelson the Presidential Medal of Freedom, the highest honor that can be given to civilians in the United States, for his role as the founder of Earth Day. As Earth Day 2000 approached, Hayes agreed to do another campaign, this time focused on global warming and a push for clean energy. Five thousand environmental groups in 184 countries reached out to hundreds of millions of people. Earth Day 2000 combined the energy of the first Earth Day with the international grassroots activism of Earth Day 1990. Earth Day 2000 used the power of the internet to organize activists, and also featured a drum chain that traveled from village to village in Gabon, Africa. This Earth Day sent world leaders a loud and clear message that citizens worldwide wanted quick and decisive action on global warming and clean energy. Earth Day has reached its current status as the largest secular observance in the world and is celebrated by more than a billion people every year. It is a day of action that changes human behavior and provokes policy changes. The fight for a clean environment continues today with increasing urgency, as the damages of climate change become more obvious every day.