On Oct. 3, 1969, a proposal to establish “Earth Day” was submitted by John McConnell to Peter Tamaris with the San Francisco Board of Supervisors. The first Earth Day was held April 22, 1970 and the modern environmental movement was born.

Gaylord Nelson, a Democratic Senator from Wisconsin was instrumental in founding Earth Day as a teach-in and to “force this issue onto the national agenda.” 20 million Americans demonstrated across the nation. Senator Nelson was awarded the Presidential Medal of Freedom by President Clinton in 1995 — the highest honor given to civilians in the United States — for his role as Earth Day founder.

However, the stage was set for change with the publication of Rachel Carson’s New York Times bestseller Silent Spring in 1962. The book represented a watershed moment, selling more than 500,000 copies in 24 countries as it raised public awareness and concern for living organisms, the environment and the inextricable links between pollution and public health.