You pick up very well-known books on Lincoln [and] you will find almost no reference to his long-term belief in colonization. Why? Because it doesn't fit the image of the Great Emancipator. It doesn't fit the retrospective view we want to have of Lincoln as the man who was the moralist in politics, who came into office committed to ending slavery and waited to sign this document.

In a democratic society, as Max Weber said, what is possible is only possible because some people have demanded the impossible. The abolitionists helped to create a public discourse in which men like Lincoln become possible. That doesn't mean Lincoln is an abolitionist. It means there is a public opinion out there which is being influenced by antislavery sentiment.

I think here is the irony of American history. We don't have an established church. When you have an established church nobody takes religion as seriously as we do here. We have a free market in religion. The religious groups are competing with each other.

Colonization was the idea that once slavery ended African-Americans should be encouraged - or required, in some people's view - required to leave the country. It's part of an attitude toward the abolition of slavery which says America should not be a slave society, but it can never be a multiracial society. You can never have free black and white people living together.

Look, Mrs. McGillicuddy, it's not my fault your son jumped out a dorm room window on Christmas eve. I've written over fifty books as a Columbia professor, all right? You don't do that by holding hands with every at-risk undergraduate who says he's homesick, or he's turning gay, or the dog ate his term paper. I write about Lincoln, and freedom, and great ideas. I don't always have time for students. It's like Dean Martin used to say: if you want to talk, go to a priest. Hey -- what's the gun for?

I don't [even] know the number of books on Abraham Lincoln. Ten thousand, twelve thousand? I have seen various numbers. It seems like every generation is always trying to come to terms with Lincoln.

Lincoln was a modernizer, so to speak. He believed in economic development. As a Whig before the war he favored what we would call infrastructure spending, government appropriation for canals, railroads, river and harbor improvements, and a tariff to protect industry. He believed in this market revolution that was sweeping across Northern society. He himself benefited from it in his own life.