That to me was one of the most exciting, and weird puzzles of this book: how are the most religious people and the least religious people of their time all drawn to very similar visions of utopia?

The thought was, 'We're going to go to California, where the soil is black and ten feet deep, and there are no rocks, and there's gold in the hills.' The West becomes the surface onto which people project their fantasies, where once the future had been the place they projected their fantasies. So it's not just the war that ends the utopian communities, but what follows.

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.

There are Harvard grads, free thinkers, feminists, abolitionists, well-to-do people who want to go write poetry and live on a farm and cook and laugh and have a good time. As they themselves described it, it was an "inward facing" community. They were focusing on making a better existence for themselves, which I think is also the driving force of 20th century communalism in the US, the thought being that the world is corrupt, and we're going to build this little garden of innocence.

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.

Some people just think utopians are idiots who are imagining rivers of candy and not really engaging with the world's ills, and sometimes that's surely the case, but I think that imagining the perfected society is a way of expressing your disgust with the current state of affairs.

The Oneida Perfectionists, along with some of the others, believed that feminism, and abolitionism, and other causes that they pursued in their own way without participating with other people outside of their communities, were all piecemeal reforms. That's what makes a utopian a utopian, this idea that they were going to create a whole new world from scratch.