Creationism is a Christian doctrine holding that the world and the living things in it—human beings in particular—were created by God. There have been a variety of creationist viewpoints, and some of these viewpoints are in conflict with mainstream scientific theories, especially the theory of evolution.

After Charles Darwin published his Origin of Species (1859), which not only defended the pre-existing theory of evolution but also maintained that evolution took place through natural selection, many fundamentalist Christians reacted with horror. Then as now, anti-evolutionists maintained that evolution was contrary to the Bible, that it was atheistic pseudo-science, and that, by proposing that man descended from lower animals, it denied man's spiritual nature. Evolutionists denounced creationists for allegedly misinterpreting both the Bible and the scientific evidence.

In the 1920s, William Jennings Bryan, a former Nebraska Senator, Presidential candidate, and U.S. Secretary of State, joined the movement to...