I thought I'd share
this interesting article on the history of the establishment clause. Steven Waldmen in the Washington Monthly:
John Adams, Patrick Henry, and others believed the First Amendment really was meant to block the formal establishment of an official church, but allowed much mixing of church and state. For instance, Adams endorsed national days of fasting and prayer and appointment of congressional chaplains. Jefferson and Madison were on the other end of the spectrum, demanding the clearest separation of church and state. As president, Jefferson reversed the practice initiated by Washington and Adams, and refused to have a national day of prayer. Madison agreed. He cited the appointment of chaplains as being a direct violation of the "pure principle of religious freedom," especially given how "strongly guarded as is the separation between Religion & Government in the Constitution of the United States."
Just as the Founding Fathers disagreed, so too did people of faith. Congregationalists and Episcopalians were the chief defenders of state-supported religion and more aligned with the views of Adams and Henry. It was the evangelicals who backed the more radical views of Jefferson and Madison. Leland, for instance, agreed with Jefferson's opposition to congressional chaplains. "If legislatures choose to have a chaplain, for Heaven's sake, let them pay him by contributions, and not out of the public chest," he once wrote. Indeed, as Rabbi James Rudin notes in his new book The Baptizing of America, "Leland was even against the Sunday closings of U.S. post offices, feeling this represented government favoritism by officially recognizing the Christian Sabbath."
In other words, the Founding Fathers were divided on separation of church and state--but most of the evangelicals weren't. They overwhelmingly sided with Jefferson and Madison.