The republic's Christian founders made it clear that no faith should have a privileged position in America and that religion should not intrude in the workings of government.
A century ago, the small Tennessee town of Dayton witnessed the infamous "Monkey Trial", which continues to haunt us.
Local high school science instructor John T. Scopes, 24, had been accused of violating a new Tennessee law against teaching Charles Darwin's theory of evolution.
As Defense lawyer Clarence Darrow questioned William Jennings Bryan, director of the prosecution, about the Bible, the trial became a symbol of the collision between faith, science, and politics.
The "monkey trial" was memorably described by the Baltimore Sun's H.L. Mencken.
Author's summary: Faith and science collide in America.