Gary Scott Smith on Theistic Rationalism:

Gary Scott Smith, Chair of the History Dept. at Grove City College, has a new book out examining the faiths of US Presidents. It's published by Oxford University Press and looks to be quite good.

Google books has a nice preview. I linked to some passages where he discusses the key Founders' "theistic rationalism." On page 26, he puts Washington, Adams, Franklin, Wilson and Jefferson in the same box -- the "theistic rationalist" box, not strict deism or orthodox Christianity.