Tennessee passed the Butler Act in 1925, making it unlawful for a state-funded teacher to teach any theory denying the biblical account of creation and holding instead that man descended from a lower order of animals. The American Civil Liberties Union advertised for a teacher willing to be prosecuted so the law could be challenged, and businessmen in the small town of Dayton took up the offer, partly for the publicity. John Scopes, a young science teacher and part-time football coach, agreed to be the defendant, and was not certain he had actually taught the material.
The trial became a national spectacle. William Jennings Bryan, three times a presidential candidate and the country's best-known populist, appeared for the prosecution; Clarence Darrow, the most famous defence lawyer in America, appeared for the defence. It was carried live on radio, and hundreds of reporters filled the town.
The famous moment came when Darrow called Bryan himself to the stand as an expert on the Bible and questioned him for two hours in the courthouse yard, drawing from him the admission that the days of creation might not have been twenty-four hours. The judge struck the testimony from the record the next day. Scopes was convicted and fined one hundred dollars, and the conviction was set aside on appeal because the judge rather than the jury had set the fine.