When the Scopes ‘Monkey’ Trial Pitted Science Against Religion

In the scorching summer heat of small-town Dayton, Tennessee, in July 1925, crowds of reporters and local residents gathered at the courthouse to watch the showdown between Charles Darwin and the Christian Church.

The trial was of John Thomas Scopes, a 24-year-old high school teacher and football coach with “carrot-colored hair” and a “pleasant demeanor,” who, with backing from the American Civil Liberties Union, had violated the newly passed Butler Act by teaching evolution in his classroom. It was the first U.S. trial ever to be broadcast live on the radio, and the whole world listened to hear the fate of evolution in America.

In the end, Scopes lost (although the verdict was eventually overturned on a technicality). But the "Monkey Trial," as it came to be known, was an important milestone in Darwin’s road to becoming a permanent fixture in the American classroom.

While Scopes may have been the unassuming defendant in the case, the real face-off was between the two lead lawyers. Fighting for the prosecution was William Jennings Bryan, a three-time presidential candidate who saw the trial as his chance to give the performance of a lifetime in his fight to defend the religious fundamentalism in which he so avidly believed.

“The contest between evolution and Christianity is a duel to the death. It has been in the past a death struggle in the darkness. From this time on it will be a death grapple in the light. If evolution wins in Dayton, Christianity goes—not suddenly, of course, but gradually—for the two cannot stand together. They are as antagonistic as light and darkness, as good and evil,” Bryan said in a speech ahead of the trial's start.

Scopes and the tenets of evolution were defended by rockstar criminal defense lawyer Clarence Darrow, who emerged as the real MVP of the trial. In a stunning performance that took place on the front lawn of the courthouse in order for the proceedings to escape the sweltering heat and crowds of onlookers indoors, Darrow cross-examined Bryan about how the Bible should be interpreted. By all accounts, he ripped Bryan’s argument to shreds. While Bryan’s side technically won the case, it was something of a defeat for him personally. Five days after the trial ended, he died in his sleep.

The official name of this legal battle may have been The State of Tennessee v. John Thomas Scopes, but it has gone down in history as the Scopes Monkey Trial, thanks to Baltimore Sun reporter H.L. Mencken’s lively coverage.

The nickname stemmed from a misreading of Darwin—the naturalist posited that humans and monkeys had a common ancestor, not that humans descended from monkeys as many fans of the prosecution contended and objected to—and it was whole-heartedly embraced. From the beginning, the trial had been just as much a spectacle as it was a serious legal affair, and the occupants of Dayton embraced their new-found fame by offering monkey souvenirs and paraphernalia. Local country singer Vernon Dalhart even released a song honoring the proceedings called “The John T. Scopes Trial.”

But perhaps the most entertaining appearance of all was that of a legendary chimpanzee, Joe Mendi, who had performed in vaudeville acts and on Broadway, but whose most famous role just might have been the antics he carried out around Dayton as he became the mascot of the trial.

While Scopes’s conviction and $100 fine were overturned on a technicality, the decision in favor of evolution was solidified on a national level in 1968, when the U.S. Supreme Court overturned a similar law in Arkansas. Still, in 2019, a Pew Research Center study revealed that 18 percent of Americans wholly reject the idea of evolution. And 2024 research showed that several U.S. states have laws that frame academic freedom as allowing the right to teach scientific controversies, including doubts about the theory of evolution.