That is the question being examined in this lengthy article in the New York Times. The article recounts historical evidence of the role of Christianity in shaping our country's institutions/ laws. Examines the question against the backdrop of current battles between secularists and Christians over public square "culture wars". It also resonates with the sound of arguments *within* the church today between religious secularism and Biblical worldview Christianity:
How Christian Were the Founders? - NYTimes.com
How Christian Were the Founders? - NYTimes.com