![The Cleveland Women’s City Club assesses the Cuyahoga River water pollution in 1966.](/sites/default/files/styles/large/public/article18-19/Women%27s%20City%20Club.jpg?itok=Wyy9HQ1C)
Women's City Club
Aboard the ship “Goodtime,” the Cleveland Women’s City Club assesses the Cuyahoga River water pollution in 1966. (Image courtesy of The Cleveland Press Collection.)
![A Greta Thunberg sculpture used in a September 2019 climate strike.](/sites/default/files/styles/large/public/article18-19/Greta%20Thunberg.jpg?itok=3eNHNIYV)
Greta Thunberg
![The 'Mood of Campus Valedictory Speakers is Somber' article.](/sites/default/files/styles/large/public/article18-19/1969%20Valedictorians_0.jpg?itok=-84KwKZj)
Somber Valedictorians
![In 1955, soap suds measuring 15-feet high covered a vehicle bridge in Valley View, Ohio.](/sites/default/files/styles/large/public/article18-19/Ohio%20Canal%20Suds.v2_0.jpg?itok=CVlxeVlL)
Ohio Canal Suds
![Workmen in 1969 using rakes, shovels, and pitchforks to clean up oil-soaked straw.](/sites/default/files/styles/large/public/article18-19/Santa%20Barbara%20Oil%20Spill.jpg?itok=xQZMk_d8)
Santa Barbara Oil Spill
![Earth Day ad in The New York Times.](/sites/default/files/styles/large/public/article18-19/Earth%20Day%20Ad.NYT_.jpg?itok=xT_mI_a0)
Earth Day Ad
The 1970 advertisement placed in The New York Times by Senator Nelson’s non-profit organization, The Environmental Teach-In. (Image courtesy of Earth Day Network.)
![University of Michigan students participate in a March 1970 pollution teach-in.](/sites/default/files/styles/large/public/article18-19/Pollution%20Teach-In.jpg?itok=Wopx7uD-)
Pollution Teach-In
![After noon on April 22, 1970, only people were allowed on New York City’s Fifth Avenue.](/sites/default/files/styles/large/public/article18-19/Fifth%20Avenue%2C%20NYC.jpg?itok=NEv5Fylb)
Fifth Avenue, NYC
![Peter Hallerman poses during a 1970 Earth Day demonstration.](/sites/default/files/styles/large/public/article18-19/Peter%20Hallerman.jpg?itok=jkfQHUKl)
Peter Hallerman
![The cast of the Broadway musical 'Hair' performed before 20,000 people.](/sites/default/files/styles/large/public/article18-19/%22Hair%22%20Performers.jpg?itok=mxBjtT1l)
“Hair” Performers
![A 1974 Environmental Action poster that depicts 12 congressmen who voted against environmental concerns.](/sites/default/files/styles/large/public/article18-19/The%20Dirty%20Dozen.jpg?itok=9QgVfoIP)
The Dirty Dozen
A 1974 Environmental Action poster that depicts 12 congressmen who voted against environmental concerns. Their faces are superimposed on a picture of an early twentieth-century “sports team.” (Image courtesy of the Smithsonian Institution.)
![A 12-foot-long shark sculpture made in 2015.](/sites/default/files/styles/large/public/article18-19/Washed%20Ashore%20Project.jpg?itok=8pPLzRWK)
Washed Ashore Project
![The Dakota Access Oil Pipeline being installed.](/sites/default/files/styles/large/public/article18-19/Dakota%20Access%20Oil%20Pipeline.jpg?itok=0CMPDo66)
Dakota Access Oil Pipeline
![Ohio teenagers earn a $1,000 grant in 2019.](/sites/default/files/styles/large/public/article18-19/Teen%20Eco%20Summit.jpg?itok=3cIZO05B)
Teen Eco Summit
Ohio teenagers earn a $1,000 grant in 2019 to create an environmental sustainability project at their high school. (Image courtesy of Piper Sullivan.)