Atheist isn't really the right word because they tended to believe in some sort of Enlightenment, capital 'N' Nature kind of god. But these were people who in their times were criticized as infidels.

One of the things that's amazing about reading the private writing of these folks is that they enthusiastically describe things which we have now seen, and which are widely regarded as unappealing. They'll write, "It's going to be beautiful, we're going to have a town of 1,000 stone buildings that are all identical." And we as modern readers think, we've seen that; that's bad Soviet architecture or a public housing project. Nobody fantasizes about living there.

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.

But if you'd only ever lived in small wooden house in the middle of wilderness, it sounded much better. Especially because it provided intense community, and these people lived in incredible isolation.

Margaret Fuller was already a celebrity, travelling around the world. Emerson, who was the axis around which that whole community turned, just didn't like Fourier's ideas very much. He thought it was all too rigid and programmatic. He said, "Fourier had skipped no fact but one, namely life." He thought it was an inhumane system - the day is scheduled too precisely. He didn't think it would work, and he was right.

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 Jacksonian era is generally talked about in terms of individualism, and the development of free market capitalism, and Victorian prudery. It was shocking to find a parallel history to that - a bunch of Americans with very different priorities. I stumbled on to these people, and then became completely fixated on them. The question that drove me was: how did these reasonable people adopt these extremely unreasonable ideas?