No, it is not a capital g. I deliberately did not capitalize, because there is no god. Where is your proof? Seeing a shining light as I swim to shore (not drown) is not proof of god, that is a common mis-perception. Our brains, made of chemicals, will create illusions as the tissues are starved for oxygen (or glucose). The brain is also known to create illusions (called auras) when there are chemical or electrical imbalances that lead to seizures. Is everyone who suffers from a seizure seeing god when they sense an aura?
No, I would not be surprised at the faith our founding fathers had. I know that many professed faith in a creator (I have actually read about some of them). That is exactly why they chose to deliberately exclude any mention of a god in oaths of office or as a part of our government: to avoid one belief system governing/persecuting/ignoring other beliefs systems.
Those who profess faith must be defensive about their faith, because to disprove it would mean they must face reality. Reality can be difficult to deal with: it is final.
Those who profess faith must destroy others to keep theirs. Atheism doesn't seek to "destroy" faith, just show that reality is real.