Taft was Roosevelt's handpicked successor. I didn't know how deep the friendship was between the two men until I read their almost four hundred letters, stretching back the to early '30s. It made me realize the heartbreak when they ruptured was much more than a political division.

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.

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

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.