Earth Day was started by U.S. Senator Gaylord Nelson of Wisconsin in 1970 as a way to bring environmental issues to national attention. Nelson was inspired to create Earth Day after witnessing the 1969 Santa Barbara oil spill and learning about the success of anti-war teach-ins on college campuses. He proposed a nationwide environmental teach-in on April 22, 1970, to engage the public and politicians in environmental protection efforts
. Nelson hired Denis Hayes, a young activist, as the national coordinator to organize the event, which grew beyond a teach-in to include rallies, marches, and community actions across the U.S. An estimated 20 million Americans participated in the first Earth Day, making it a massive grassroots movement that helped spur the creation of the Environmental Protection Agency and new environmental laws
. The name "Earth Day" was coined by advertising writer Julian Koenig, and significant support came from labor unions such as the United Auto Workers, led by Walter Reuther, who provided crucial funding and organizational help
. In summary, Gaylord Nelson is credited as the founder of Earth Day, with Denis Hayes playing a key role in organizing the first nationwide event on April 22, 1970
