The Old Testament mythology has its god as an over-dramatic individual, DIRECTLY interfering in human affairs.
Deism is the polar opposite of such a concept- in that its main ideology is that there is no such interference- a mere stepping stone to formal Atheism.
Sadly, you are so clueless you don't realize that the New Testament also depicts a God who directly intervenes in human affairs, to the point of becoming one of us.
You are correct, this is why a key founder such as Jefferson cannot rightly be called Deist:
And can the liberties of a nation be thought secure when we have removed their only firm basis, a conviction in the minds of the people that these liberties are the gift of God? That they are not to be violated but with his wrath? Indeed I tremble for my country when I reflect that God is just: that his justice cannot sleep for ever . . . .
-Notes on the State of Virginia
Not exactly the words of a man who thinks God never interferes.
To be fair, most of the founders were nominal Christians...not evangelical (the evangelical/liberal split had not yet occurred in Protestant Christianity), with a few Deists--the fashionable philosophy of the day--sprinkled amidst them. It was scandalous however to even be accused of being Deistic, and various ones denied the charge...
While I would agree Deism--socialogically--is a "stepping stone" to atheism (an absent God affects you no more now than a non-existent one), still, for its adherents, it is different.
The key relevant difference for our founders is--they believed our rights were made by God, embedded in our very nature. No atheist can logically argue that.