Though [Abraham Lincoln] never would travel to Europe, he went with Shakespeare's kings to Merry England; he went with Lord Byron poetry to Spain and Portugal. Literature allowed him to transcend his surroundings.

As a historian, what I trust is my ability to take a mass of information and tell a story shaped around it.

If you interview five people about the same incident, and you see five different points of view, it makes you know what makes history so complicated. Something doesn't just occur. It's not like a scientific event. It's a human event. So the dimensions of it will be seen differently by different people.

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.

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.

I think the most important thing I wanted to say at various times to Franklin and Eleanor Roosevelt was that it seemed so sad to me that - I really believe they loved each other and had a great deal of affection - but because of that early hurt in their marriage, there was a certain kind of distance from then on, until their deaths actually. So at times, I just wanted to push them together and say, "Come on, you guys! I know you love each other. This is crazy!"

I think the most important advice is, a person doesn't have to find out right away. It's not like their first attempt at finding a profession is the only one they're going to find. I might well have gone down other paths, and it still might have been okay. But if you find something that you love, and if it keeps deepening with each new experience, then just stay with it.