What interested me most about the Kennedys was the family situation. Somehow, they had created this family that lasted over time, they had a sense of connection to one another. Especially now, when people are spread all over the country and they don't see grandparents and parents, this family bonded together.

I think with Lyndon Johnson, the most important thing I learned was that he never had the sense of security that comes from inside. It always depended on other people making him feel good about himself, which meant that he was always beholden, continually needing to succeed. He could never stop. There was such a restlessness in him.

My books are written with a strong chronological spine.

I liked the thought that the book I was now holding had been held by dozens of others.

Washington was a typical American. Napoleon was a typical Frenchman, but Lincoln was a humanitarian as broad as the world. He was bigger than his country - bigger than all the Presidents together.

When I do research, I have done - 90 percent of my time is the research, the other ten percent is the writing. So I don't have to face a blank piece of paper. I can look at this as a quote that I have from somewhere.

The White House is such an extraordinary, simple, beautiful place. It's an extraordinary piece of our history, because it is the one thing that binds our country together. We don't have a king obviously, but we have this president, and the fact that almost all of them have lived in the same place, and so much history took place in those rooms. You can't help but feel awe-inspired by being there.