What surprised you most in your research?
The most unexpected thing, I think, was my discovery that Benjamin Franklin had a wife in Philadelphia and a [woman] in London. For 20 years before the Revolution, Franklin was in London trying to prevent the Revolution from exploding. He was boarding with a woman named Margaret Stevenson. She was the total opposite of the woman he had married in Philadelphia when he was a very young man. Pretty soon, they were being invited out as a couple. Margaret wrote to him after he returned to America, in which she basically said, "I hope we get married soon." And unfortunately for her, and I think for Franklin too, that was impossible. Because when Franklin came back from England, the Revolution had begun. And this was the biggest heartbreak of Franklin's life.