So there's that change of general consciousness, and then there's this boom after the war, this expansion into the West. It was like the 1950s. The American economy was pumping at top speed. The kinds of people who would move into these communities and organize their lives around a utopian dream now had dreams about the West.

Utopians don't say, 'The world's corrupt, women make less money, people of color are oppressed at every turn.' You don't list the problems of the world; you describe a world in which those things aren't the case. The critique is implicit and as a result it's kind of a positive critique. You're not listing what's bad, but rather what would be good - you're oriented toward this positive vision.

I was really interested in 20th century communalism and alternative communities, the boom of communes in the 60s and 70s. That led me back to the 19th century. I was shocked to find what I would describe as far more utopian ideas in the 19th century than in the 20th century. Not only were the ideas so extreme, but surprising people were adopting them.

I worry that I may have overstated the impact of Civil War on the utopians. By the time the Civil War comes, most of the communities were quite separated from the wider American society. Their rhetoric is still about transforming the world, but they're not having that much traffic with their neighbors.

These weren't college kids on acid. They were preachers, and bankers, and farmers, and the salt of American society subscribing to ideas that now seem so wild to us. These people had the most radical visions of what the future could be. And this was happening in an era we don't typically associate with sexual experimentation, or communism, or things like that.

The Enlightenment faith that things are getting a little bit better each decade becomes difficult to support. People recognized that there had just been a war that was worse than the war of 1812, and worse than the Revolution; things were clearly not getting better and better.

Utopian fiction is really boring. I had to read a lot of it, and it's not that much fun. But they're fascinating to me as historical documents. Cabet [Icaria's founder and author of the utopian novel, Travels in Icaria], is writing in the 1830s, and his idea of the perfect society reveals a lot about his time. But his book is uniquely bad.