 Zimmerman was a veteran of similar disputes in Ohio, when he was a professor at Oberlin College.After Zimmerman watched Christian fundamentalist clergy from Dover, Pennsylvania, on the television program "Nightline" insisting that decisions about teaching evolution in schools was equivalent to a choice between heaven and hell, he recruited the husband of the head of the university Psychology Department, John McFadden, pastor of the First Congregational United Church of Christ in Appleton, Wisconsin, to write a letter describing how science and religion can co-exist.Zimmerman worked with local clergy in Wisconsin to get clergy to sign this letter, and within a few weeks he had collected almost 200 clergy signatures.