The American Civil Liberties Union (ACLU) hired Clarence Darrow to represent John T Scopes.
The Scopes Trial was a famous case during the 1920's that involved whether or not the theory of evolution should be taught in school. This case was focused around the idea of how do religion and science mesh in the public school setting. The ACLU hired Darrow for this case due to his incredible background and success as a defense attorney in the US.