I knew Jefferson was down with religious pluralism...

...but I didn't know about Ben Franklin:

Ben Franklin, the founding father of many important institutions in Philadelphia, a key diplomat and a framer of the US Constitution, wrote in his Autobiography concerning a non-denominational place of public preaching he helped found "so that even if the Mufti of Constantinople were to send a missionary to preach Mohammedanism to us, he would find a pulpit at his service."

[ History News Network ]

Interesting and well stated article, it would seem that much thought was put into freely accepting Muslims in the fabric of America even way back at the beginning.