There are no Jewish residents in the small, coal-mining town of Whitwell, Tennessee. It’s predominantly white, Anglo-Saxon, and Protestant—yet it’s also the home of one of the world’s most poignant Holocaust memorials. Over the past 20 years, Whitwell has become a pilgrimage site for student groups, religious congregations, and even motorcycle clubs, who gather there to remember the victims of the Nazi regime.

It all began with the town’s visionary middle school principal. In 1998, Linda Hooper grew wary of the town’s homogeneity. “We just have to give our children a broader view of the world,” she later told the Washington Post. “We have to crack the shell of their white cocoon, to enable them to survive in the world out there.” She prompted Sandra Roberts, the school’s beloved language arts teacher, and David Smith, the associate principal and football coach, to develop an eighth-grade after-school program about prejudice and tolerance.

Roberts and Smith chose to teach about the Holocaust—an unfamiliar topic for their students, since this portion of history wasn’t part of the middle school’s curriculum. The teachers began by reading aloud first-hand accounts of the war, such as Anne Frank’s The Diary of a Young Girl (1947) and Elie Wiesel’s Night (1956), to the class of 16 students. Many of them could not afford to buy these books themselves; Whitwell was largely a low-income community, and over half of the school’s students qualified for free lunch.

One day, a student (though no one quite remembers which one) asked the group, “What is 6 million? I’ve never seen 6 million.” In response, the class decided to collect 6 million of something to help visualize the magnitude of Jewish deaths during the war. In the end, they decided upon paper clips. Many Norwegian students, they had learned, wore paper clips on their lapels as an act of quiet protest during the war. They were also small and cheap enough to collect en masse—and, moreover, could serve as symbols of unity, attachment, and interconnectedness.

And so it began. Students ruffled through their own drawers, then recruited neighbors and friends to donate as well. To gain exposure, they set up a website and started writing letters asking for additional paper clips. These were the days before crowdfunding and ice bucket challenges; the students couldn’t have imagined that their project could go viral.

One of the earliest mailed-in paper clips came from Lena Glitter, a 94-year-old Holocaust survivor living in Washington, D.C. Soon, celebrities joined in: then-president Bill Clinton, Tom Hanks, Steven Spielberg, the Tennessee Titans, and the Dallas Cowboys, among others. By the year’s end, the students had gathered about 100,000 clips.

The Paper Clips Project gained worldwide attention in 1999, when two German journalists living in Washington, D.C., wrote about the school. The Washington Post picked up the story two years later, and in the six weeks following publication, over 24 million paper clips flooded the small Tennessee town. “Grandmothers counted paper clips, aunts counted paper clips, cousins, mamas, kids, anybody who had a spare minute counted paper clips,” Hooper later recalled in an interview with Junior Scholastic.

Many of the paper clips arrived with personal letters, dedicating their donation to specific Holocaust victims and sharing personal stories about the war. “Today, I am sending 71 paper clips to commemorate the 71 Jews who were deported from Bueckeburg,” reads one letter. “For my son, that he may live in peace,” reads another.

In all, the school received over 30,000 documents, photographs, and other artifacts, which the students archived in large three-ring binders. “We kept every piece of paper, regardless of size, from scraps of paper to stamps,” Roberts, the language arts teacher, told Scholastic.

As for the paper clips? The class stopped counting when they hit 30 million. From mail sorters to community organizers, the students were now ready for their next role: exhibition designers. (For guidance, the students could have looked to a number of contemporary artists employing everyday objects as a way to process suffering. In the early 1990s, for instance, Cuban-American conceptualist Felix Gonzalez-Torres exhibited 175-pound piles of candy to represent the fluctuating weight of his partner suffering from AIDS. More recently, Chinese artist-activist Ai Weiwei plastered historic buildings across Europe with orange life vests to remind passersby of the refugee crisis.)

With the help of Peter Schroeder and Dagmar Schroeder-Hildebrand, the journalists who had first broken the story, the students acquired one of Germany’s last “cattle cars”—train cars which had been used to transport Jews and other victims of the Holocaust between ghettos, labor camps, and death camps. They filled the space with 11 million paper clips, representing the 6 million Jews and 5 million non-Jews who perished under the Nazis. Around the lawn, they placed mosaic butterflies, inspired by a poem written by a child in the Theresienstadt ghetto.

2018 marks the 20th anniversary of the unlikely memorial. “You would think after 20 years, there would not be much interest among the students about the project,” Hooper told Artsy. But, she said, the children still ask to serve as guides during weekly memorial tours. “What surprised me most is its endurance and the interest people have shown in it—all groups of people, not just Jewish people.”

“The project really increased our awareness of how we speak to people,” continued Hooper, who’s since retired as the school’s principal and currently serves as the town’s mayor.

“This makes us more aware of who we are, what we have to offer, and what we need to offer our communities.”