That comment and this response ended up in my inbox.:
Not really. We were founded by people with a broad range of beliefs, from extremely Christian to complete atheists. The Founding Fathers were generally products of the Enlightenment, which encouraged skepticism and free thought.
Many of the most famous considered themselves "Deists", who believed in some sort of vague supreme being, but openly doubted the literal truth of Christian dogma. Almost to a man, they made statements which would render them completely unelectable today. Samples here.
In many ways, religious debate reached its peak of maturity around the time our nation was founded, and has been going downhill ever since.