Those who knew Lincoln described him as an extraordinarily funny man. Humor was an essential aspect of his temperament. He laughed, he explained, so he did not weep.

That is what leadership is all about: staking your ground ahead of where opinion is and convincing people, not simply following the popular opinion of the moment.

I really believe that what happens one day affects the next, and I think that came from that experience of learning that if I told the score inning by inning, play by play, it built up to its natural climax.

The only protection as a historian is to institute a process of research and writing that minimizes the possibility of error. And that I have tried to do, aided by modern technology, which enables me, having long since moved beyond longhand, to use a computer for both organizing and taking notes.

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