There was specific constitutional provision for emergency measures in the case that Abraham Lincoln faced - an insurrection - which no other president has faced.

I am asked often about Abraham Lincoln's mistakes and faults; he certainly made some mistakes. I have chapter in President Lincoln about the Powhatan affair that was a royal screw-up in the early days - right alongside the Sumter affair. Lincoln signed letters he should not signed, and the ship was sent to two places at one under two captains etc. Fortunately, no great harm. Lincoln took the blame and did not do anything like that again.

Yes, the rise in corporate power had roots in the gearing up for the Civil War. Abraham Lincoln was a Whig, a supporter of government aid to expanding industry - to "internal improvements" that supported the growth of business. He was an early capitalist, not one who wanted to preserve some rural paradise.

After I published a book called Lincoln's Virtues a wit said that my next book should be Lincoln's Vices. But in my opinion that would be a short book!

When I went to an Aspen seminar on "American Scriptures" - the bicentennial of the Declaration and they discussed the preamble and the Gettysburg Address and much more, but not Lincoln's Second Inauguration, I challenged that omission and they said find something on it and to my astonishment, at that time, there was no book or long article that really did it. So I wrote one that attempted to do it justice. Although obscurely published, that essay got a nice bounce. Somehow David Donald saw it, and in his notes to his biography singled it out.

The situation Abraham Lincoln faced was unique. In his view, the United States was threatened with destruction, ruin, overthrow, perishing - all words that he used - which is not the case for any other president, including the current one - Barack Obama.

It is very hard to answer the oft-posed questions about how Abraham Lincoln would respond to some current condition. My favorite story on that count is that the late great Lincoln scholar Don Fehrebacher was asked, during the struggles over bussing for racial balance a few years ago, what Lincoln would say about "bussing" and he thought awhile and then answered : "what Lincoln would say would be: "What's a bus?"