Whatever Lincoln's racial views, which are not totally modern and egalitarian in many ways, he believes blacks should have this natural right to improve their condition in life and slavery denies that to them.

Lincoln is such an iconic figure in American history. He seems to reflect so many elements of American culture that we consider essential, whether it's the self-made man, the frontier hero, the politician who tries to act in a moral way as well as in a political way, Honest Abe. His career raises these questions that are still with us, the power of the federal government vis-à-vis the states, the question of race in American life, can we be a society of equals? There are so many issues central to Lincoln's career that are still part of our society one hundred and fifty years later.

For historians, hindsight can be a treacherous ally. Enabling us to trace the hidden patterns of past events, it beguiles us with the mirage of inevitability, the assumption that different outcomes lay beyond the limits of the possible.

I admire Lincoln enormously and I think what's interesting about Lincoln is how he changes, it's not that he held the same view throughout his life.

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.

Freedom has been privatized - it is how you dress, what your sexual orientation is, choosing your own life. That's fine. But that is not what Thomas Jefferson was talking about.

Who owns history? Everyone and no one--which is why the study of the past is a constantly evolving, never-ending journey of discovery.