I'm glad you're able to read the minds of guys who have been dead for 200 years so much better than the judges appointed to the Supreme Court.
There is no mind reading needed. Look at the writings of these individuals. Look at the way they lead their own lives.
They took actions which would really make atheists angry if someone tried it today.
There is a reason our money says "in God we trust". They put up the ten commandments in public buildings for a reason. They even held christian church services in the Capitol building, for goodness sakes.
Those are the first examples that comes to mind off the top of my head. There are plenty more where that came from if you simply do the research.
Their intent was to make sure the government couldn't tell them what to believe (as many of them had been subjected to prior to coming to America). They didn't want someone dictating their religion to them.
Their intent was NOT to remove religion from government, but to remove government from religion.
If they had only made that more clear, the atheists would have to whine and cry about something else.