Just before he died, Benjamin Franklin was asked about his religious beliefs. Here is (in part) what he said:
“Here is my creed: I believe in One God, the Creator of the Universe. That he governs the world by His providence. That he aught to be worshipped. That the most acceptable service we can render to Him is doing good to His other children. These are the fundamental principles of all sound religion.”
Regarding Jesus (peace be upon him):
“I think his system of morals and religion, as he left them to us, the best that man ever saw or is likely to see. But I apprehend that over time, it has received various corrupting changes.”
“I have some doubts as to his divinity, though it is a question I do not dogmatize upon, having never studied it, and think it needless to busy myself with it now when I expect soon an opportunity of knowing the truth with less trouble.”
This was taken from a lecture given by Geoffrey Stone at the University of Chicago School of Law, entitled "The World of the Framers: A Christian Nation?"
How much of this conflicts with Islam? If a person told me today what Benjamin Franklin said, I would have a hard time arguing that this person could not be a Muslim. That said, Franklin was definitely not a Muslim. But the important thing to understand from this quote is his egalitarian view of religion. He, and most of the other founding fathers never meant to create a Christian nation, but to create a pluralistic society based on shared values and human rights.
Muslims are not alien to America, but an essential and deliberate thread in the American fabric.