7 things to know about the history of Earth Day

The inaugural celebration

Crowds pack 5th Avenue in New York City during the city's first Earth Day celebration 1970.

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The first Earth Day was hosted on April 22, 1970.

Celebrations were held across the United States, with the two largest gatherings located in New York City and Washington, D.C.

According to the Environmental Protection Agency (EPA), more than 20 million people participated in the first Earth Day events around the country. Today, nearly 1 billion people celebrate Earth Day worldwide.

Earth Day’s founding father

U.S. Senator and founder of Earth Day Gaylor Nelson stands in Rock Creek Park in Washington, D.C.

(Janet Fries / Getty Images)

The first Earth Day was spearheaded by Senator Gaylord Nelson of Wisconsin.

A former governor of the Badger State, Nelson had a long history of promoting conservation efforts in his homestate and across the country. The senator had a number of accomplishments, such as banning DDT and preserving the Appalachian Trail.

Nelson and his Senate staff enlisted the help of law student Denis Hayes to serve as the national coordinator of Earth Day efforts.

The power of student activism

Messages are scrawled onto the streets of New York City on Earth Day 1970.

(Santi Visalli / Getty Images)

Young people made the first Earth Day possible.

According to Encyclopedia Britannica, Nelson and Hayes recognized the energy of student-led anti-war activism and wanted to infuse that energy with what was a relatively new environmental consciousness in the general public.

Nelson and Hayes sought to harness this environment-focused energy of young people to help push forth environmental priorities in national politics.

Why April 22

Crowds gather by a George Washington statue in Union Square for Earth Day celebrations, New York City, April 22, 1970.

(Hulton Archive / Getty Images)

The focus on making Earth Day a youth-led grassroots movement helped sway the decision on when to host the first Earth Day.

According to the U.S. Senate, Nelson’s team believed the ideal time for college students would be the week of April 19 to 25, and they determined that students were more likely to be on campus on Wednesdays.

Combined with the greater chances of favorable weather in the spring, Nelson’s team pinpointed Wednesday, April 22 to be the date for Earth Day in the U.S.

Propelling environmental policy

Silhouette of a California brown pelican, which has been on the Endangered Species List since the 1970s.

(David McNew / Getty Images)

The first Earth Day celebration played a significant role in garnering support for environmental legislation, according to Encyclopedia Britannica.

Legislation included the Clean Air Act and the Endangered Species Act, which Congress passed in 1970 and 1973, respectively.

Creating the EPA

The Environmental Protection Agency (EPA) building in Washington, D.C.

(Stefani Reynolds / Bloomberg / Getty Images)

In the months following the first Earth Day, the increased push for environmental legislation led to the establishment of the Environmental Protection Agency (EPA).

According to the EPA, President Nixon announced his plan to found the EPA in July 1970, and the organization was officially established in December 1970.

A long history of conservation

Naturalists John Burroughs and John Muir seated on a group of large rocks. The two helped pioneer the early conservation movement in the U.S. in the late 19th and early 20th centuries.

(Bettmann  / Getty Images)

The EPA and Earth Day initiatives were part of a long history of conversation efforts in the U.S.

In the collection "The Evolution of the Conservation Movement", the Library of Congress documents the American conservation movement starting over 120 years prior to the first Earth Day. Some of the early efforts to protect the environment included the designation of national parks.