Unfortunately, it's not a fact.
A significant number of people in the colonies were Deists, Jews, or of other religious persuasions. There were also many agnostics and atheists - Ethan Allen, for example, was reputed to be the most atheistic and profane man in the colonies. I also believe that Thomas Paine was also reported to be an atheist.
The majority *were* some flavor of Christians, and the majority of *those* were Protestants, true, but they were by no means an overwhelming majority in either case. Not that I support either point of view here, just correcting the record.
"Unfortunately, it's not a fact. "
It is a fact that in the late 1700s the vast majority of the people in the US were Christians. That numbers has been estimated at 99%.
What you're doing is selecting a few people and say, "see these people were not Christians or were atheist."
You remind me of the Crest commercial years ago, in which it stated that "3 out of 4 dentist recommend Crest toothpaste." What was found out, and the maker of Crest admitted to it, was that they were using a sample of 4 dentist and asking them their preferences for toothpaste. Once they had a sample in which 3 out of 4 respondents preferred Crest toothpaste, they used this to project to the whole dentist population as 3 out of 4 preferring Crest.
It's easy to lie with statistics, you know, and fool the people.