America's founding fathers broke with the tradition of state-sponsored religion when they separated church and state in the new republic. But religion continues to divide Americans, and one of the key disagreements is over what the early leaders themselves believed.
In the final years of his life, former U.S. President Thomas Jefferson took a knife and cut up the Gospels, holy scripture to Christians.
"Even though he realizes as Republican party leader, that this would be a very controversial act," noted Harry Rubenstein of the Smithsonian's National Museum of American History, who led the project to restore the book that the third U.S. president created out of what he saved.
The Life and Morals of Jesus of Nazareth, or The Jefferson Bible as it's known today, left out the Resurrection and other miracles. Rubenstein says that's because Jefferson wanted to highlight Jesus' moral teachings.
"I think in one sense this is a larger project that he has been thinking about along with his colleagues and very close companions: what should be the moral basis of the new nation," he said.
Earlier this year, Luis Granados of the American Humanist Association published a version and sent it to lawmakers.
"There's some great wisdom in there, and we think members of Congress would be well advised to spend a few hours sitting around thinking about that - and at the same time well advised to recognize that there's some other stuff in there that's maybe not so good," he said.
He said Jefferson wasn't the only iconoclast. George Washington prayed but refused communion, while author Thomas Paine called religions "human inventions."
Thomas Jefferson was inspired by George Mason's views on freedom of conscience and the founding fathers are generally seen as Enlightenment rationalists. But the Christian right - which considers America's founding to be part of God's plan - insists their religious convictions were rock solid, for the most part.
Texas pastor Mark Collins dresses up as George Washington and makes appearances at churches and religious events. He said Jefferson cut up the Bible during a crisis of faith.
"You know, we go through seasons, and we make mistakes and sometimes we get angry at God," said Collins.
At the Jefferson Memorial in Washington, an inscription quotes the president saying, "all men shall be free to profess... their opinions in matters of religion."
Lindsey Lange, a visitor, said the founding fathers believed in pluralism.
"I believe that they were mostly open to all religions, and that's why people were coming here to the United States, escaping oppression in other countries," said Lange.
Another visitor, Elisha Troyer, agreed partly. "But I do believe with them having the Christian values that they are more on the Christian faith," she said.
Jefferson was the great thinker of America's early presidents. And he only meant to share his more radical thoughts with close friends, fearing they could stir controversy for generations to come.