How the First Earth Day Sparked an Environmental Revolution

February 27, 2020
Earth Day
Courtesy of University of MichiganAt the first Earth Day, in 1970, 20 million Americans took to their city squares and campuses to call for an environmental revolution.

Half a century ago, 20 million Americans took to their streets, parks, and campuses to celebrate the planet and decry the environmental degradation they saw around them. Earth Day 1970, America’s first, set the stage for milestone laws and regulations that protect the health of people and planet and sparked a global environmental movement that continues today.


January 1: The National Environmental Policy Act (NEPA) establishes a federal responsibility to “preserve important historic, cultural, and natural aspects of our national heritage.”

April 22: Ten percent of the nation participates in the inaugural Earth Day, which features coast-to-coast demonstrations demanding environmental protection be part of the national political agenda.

December 2: The Environmental Protection Agency (EPA) forms to consolidate all federal environmental research, monitoring, standard-setting, and enforcement.

December 31: Congress amends the Clean Air Act of 1963 (CAA) to expand the federal environmental mandate set forth in the NEPA. The EPA is granted the power to set air quality standards.

Marc St. GilChemical plants, like this one in Lake Charles, La., were considered a prime source of water pollution before the passage of the Clean Water Act in 1972.


October 18: The Clean Water Act becomes the primary federal law in the United States governing water pollution.

December 31: EPA outlaws harmful insecticide dichloro-diphenyl-trichloroethane, or DDT. Bald eagles, peregrine falcons, and other endangered bird populations begin to rebound.


December 27: The Endangered Species Act protects “critically imperiled species from extinction as a consequence of economic growth and development.

Erik CaloniusMary Workman, of Steubenville, Ohio, held a jar of undrinkable water her well and filed a damage suit against the nearby Hanna Coal Company.


December 16: The federal Safe Drinking Water Act becomes law.

December 31: Congress passes the Forest and Rangeland Renewable Resources Planning Act, requiring that the Department of Agriculture inventory the nation’s forests and rangelands, including recreation resources, for preservation.


CAA emissions standards take effect. All vehicles must now feature catalytic converters to control exhaust emissions, and lead is phased out of gasoline. Lead concentration in the air has dropped by more than 90 percent since 1980.

Lyntha Scott EilerMotorists wait in line at the safety lane at an auto emission inspection station in downtown Cincinnati, Ohio, in 1975, the same year new emissions standards took effect under the Clean Air Act.


August 7: Congress amends the CAA to protect air quality in national parks, wilderness areas, monuments, and seashores.


November 15: A bipartisan Congress amends the CAA to address acid rain, stratospheric ozone depletion, and toxic air pollution, and create a market-based cap-and-trade approach to reduce power plant emissions that cause acid rain.


October 15: A multi-year EPA report shows that the CAA’s public health protections and environmental benefits exceed its costs by a four-to-one margin.


Scott ButnerIn 2008, the EPA adopted tighter standards for ozone pollution.


EPA adopts a tighter standard for ozone pollution, though much weaker than the level recommended by its own science and health advisers.


EPA finalizes, under the CAA, the first national regulation addressing greenhouse gas (GHG) emissions for light-duty vehicles.

USFWS photo/Steve MartaranoA power plant hums near Chipps Island, Penn., in 2012. The Clean Air Act’s Clean Power Plan, which limited greenhouse gases from power plants, took effect in 2015.


EPA finalizes the CAA’s Clean Power Plan, the first limit on GHGs from existing power plants, the largest source of carbon pollution at the time. This pivotal clean air program was rolled back in 2019.


Earth Day, April 22: 196 nations sign the historic Paris Agreement, a global commitment to address climate change by reducing greenhouse gas emissions. Despite fiery objections from the environmental community, the United States exited the agreement in 2018.

U.S. Fish and Wildlife ServiceAlmost half the land on Umbagog National Wildlife Refuge in N.H. and Maine has been conserved through Land and Water Conservation Fund dollars.


March 12: Permanent re-authorization of the Land and Water Conservation Fund is signed into law, after receiving bipartisan congressional support. Since 1964, LWCF has invested royalties from federal offshore oil and gas leases to improve and expand public lands. Join AMC’s campaign to permanently fund the program.


April 22: In celebration of the 50th anniversary of the first Earth Day, AMC is organizing virtual events all month as part of its #BeOnlineWithAMC campaign.


Steve Holt, associate editor at AMC Outdoors, contributed to this timeline.



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Liam Martens

AMC Conservation Policy Fellow