The ideas of 1776 actually began well before that time.
History is linear and ideas build up over time with many different influences.
There are a few honest historians who try to make these points but most are ideological hacks using spin to make their points
Even those you identify as "honest historians," however, over several decades now, have been hampered in their research, because the so-called "liberals," now "progressives," over a period of several decades, did a masterful job in removing from the shelves of libraries and of schools the books that contained the early histories.
On the other hand, however, their efforts are being reversed now by the new technologies which have allowed the ancient volumes and later histories to be digitized and available at the click of a mouse in any home or office.
Something about that is delightful, don't you think? Almost as if "Divine Providence," as the Founders identified it, was having a hand in restoring what had been "hidden."