I want to write for history, not for the moment.

Well, there were several things. One was that the industry itself built in Detroit was abandoning the city - taking factories elsewhere, the corporate headquarters elsewhere.

I want my books to last, to stand the test of time, and to do that I focus on the forces that shape the subject - the cultural and sociological geography - to capture them in a way that will explain them no matter what they are doing.

I look for two things when I am about to launch into a book. First, there has to be a dramatic arc to the story itself that will carry me, and the reader, from beginning to end. Second, the story has to weave through larger themes that can illuminate the world of the subject.

Detroit was an exaggeration of what was going on across the country. You could see the divisions, even within the Civil Rights Movement of that period. At the same time that Martin Luther King was talking about his dream, Malcolm X gave his most famous address in Detroit during that same period, "The Message To The Grass Roots," dismissing the notion of integration.

So, I mean, there's still vast swaths of the city that are suffering from a lack of jobs and poor housing and poor public schools, but they are building momentum - you know, techies, foodies, artists, musicians, all coming to Detroit. So there is this vibrancy. You see it in the newspapers every day - some story about the new Detroit.

Well, there is something beautiful about ruins. I mean, in one sense it's not that different from going to Rome and looking at the Forum. But it's changing. It truly is. I'm optimistic but skeptical.