DuBord at one point asked the guide, "Can you tell me about these men's religious affiliation?"
The response was a series of statements that discounted the religious faith of the Founders, he wrote.
"The NPS guide went from being an expert on the Founders to someone who was fumbling to formulate his words and get even a coherent and accurate sentence about our Founders' religion," DuBord wrote. "It struck me from his initial utterances on their religious views that he knew very little if anything about the real issues at all – and that made me wonder how many presentations he had done over the years to school children and guests from all over the country and world without ever discussing the Founders' religious nature with any accuracy."
Among the guide's statements that DuBord challenged:
"George Washington didn't even attend church!"
"While the NPS guide physically hunched over, mimicked and mocked one carrying and swinging an oversized Bible in his hand, he said to the crowd: 'Even if I said the founders were Christians, how could we really know? Just because people carry a big ol' Bible in their hand, they can still be atheists!"
"Most of these men owned slaves. How could good Christians do that?"
"We know that Benjamin Franklin was a deist."
"We don't really know for sure about their religion. It's open for interpretation. You'll have to do your own study on that."
"In the very house in which they adopted a Creator-filled Declaration of Independence, not one positive comment was made about any one of the Founders' Christian faiths," DuBord wrote.
He said the group was stunned, then ordered quickly by the guide into the next room.
But in the letter, DuBord said the statements just aren't right.
"Washington attended Christ Church (the first Episcopal Church) just a few blocks away from Independence Hall with Betsy Ross, John Adams (our 2nd president), Benjamin Franklin, Benjamin Rush, Robert Morris and many other signers of our founding documents," he wrote. "He also had reserved pews at two churches in Virginia, at Pohick Church near Mount Vernon and one at Christ Church in Alexandria.
"The NPS guide could have cited any of a number of examples in Washington's life and even presidency," he wrote, citing Washington's reference as he took the oath of office in 1789 that, "we ought to be no less persuaded that the propitious smiles of Heaven can never be expected on a nation that disregards the external rules of order and right, which Heaven itself has ordained."
He reported, too, that during Washington's first inaugural, the president praised God, saying it would be improper "to omit in this first official act, my fervent supplications to that Almighty Being who rules over the Universe, who presides in the Councils of Nations ... that his benediction may consecrate to the liberties and happiness of the people of the United States."
Ten years later, DuBord wrote, Washington addressed some Delaware chiefs, saying, "You do well to wish to learn our arts and ways of life, and above all, the religion of Jesus Christ. ... Congress will do everything they can to assist you."