<question-block>In which year was Earth Day first celebrated in the United States?<question-block>

<block-quote>And the answer: 1970.<block-quote>

Photo credit: earthday.org [https://www.earthday.org/history/].Inspired by thestudent anti-war protests of the 1960s, Senator Gaylord Nelson founded Earth Dayon April 22nd, 1970 to raise awareness about environmental issues and transformpublic attitudes. It was later also adopted by the United Nations with the nameInternational Mother Earth Day.In July 1970, the Environmental Protection Agency (EPA) was established inresponse to the growing public demand for cleaner water, air, and land. Largelyinspired by the recent rise in climate-minded protests, the EPA increasedenvironmental awareness with a mission to protect public health. Earth Day wasthe precursor of the largest grassroots environmental movement in U.S. history,as well as the impetus for national legislation such as the Clean Air and CleanWater acts. At the turn of the 21st century, the EPA announced new requirementsfor improving air quality in national parks and wilderness areas andestablishing regulations requiring more than 90% cleaner heavy-duty highwaydiesel engines and fuel.However, an American conservation movement existed long before Earth Day came tobe. Efforts to create national parks such as Mt. Rainier, Yosemite, Acadia, andthe Grand Canyon were made possible through the creation of the National ParkService. Early conservationists such as John Burroughs, John Muir and LuisAgassiz Fuertes are also considered to be cultural and political founders ofEarth Day, as their efforts to create documentation of majestic naturallandscapes were fundamental in law-making regarding national parks. Learn more about the history and significance of Earth Day here[https://www.history.com/this-day-in-history/the-first-earth-day].