Library of Congress visitors can reportedly request to view the 8-by-10 inches glass plate image, which was done in a method of photography more than 150 years old.
Thunberg, 16, visited the Standing Rock Indian Reservation located in North Dakota and South Dakota back during her trip across North America to raise climate awareness.
An image of the visit was preserved on two glass plates, one of which has been archived by the Library of Congress and the other which is set to arrive in the Swedish History Museum in Stockholm, the Herald reported.
Photographer Shane Balkowitsch told the newspaper the wet plate photo of Thunberg is his “most important work to date.”
The image was reportedly used by at least 15 publications and was liked more than 1 million times across social media platforms.
Balkowitsch told the newspaper he originally sought a photoshoot with Thunberg at his studio in Bismarck but she didn’t have time, and he asked if he could come to Standing Rock to take her photo. He was given 15 minutes, he said, but when the time was up Thunberg’s father told the photographer he could take one more photo which ended up being the chosen shot.
Thunberg shared Balkowitsch’s photo last month in an Instagram post thanking everyone she met during her visit across North America.