Evolution was a theory that had existed for some time prior to the Scopes trial. However, the rise in popularity of Darwinian concepts, combined with an accumulation of fossil discoveries in the beginning of the 20th century, mean that school textbooks became more Darwinian to reflect the prevailing scientific opinion. Mandatory school attendance laws and the increased number of public high schools meant that more American children than ever were being exposed to the concept of human evolution. Fundamentalists objected to the teaching of Darwinian evolution to their children, as the doctrine of the survival of the fittest left no room for a Creator.

This objection led to the Butler Act, an antievolution statute in Tennessee that made it a misdemeanor to teach any form of human evolution in public school education. This law was challenged during the Scopes trial of 1925. It should be noted that while William Jennings Bryan championed antievolution legislation, he believed in the general concept of evolution. However, he did not believe that evolution should be taught as proven fact. For the media at the time and many historians, the Scopes trial came to represent the debate between religion and science.