Before 1870, humanity lived in dire poverty, with a slow crawl of invention offset by a growing population. Our ancestors would have presumed we would have used such powers to build utopia. But it was not so. When 1870–2010 ended, the world instead saw global warming; economic depression, uncertainty, and inequality; and broad rejection of the status quo. Economist Brad DeLong’s book tells the story of how this unprecedented explosion of material wealth occurred, how it transformed the globe, and why it failed to deliver us to utopia. Of remarkable breadth and ambition, it reveals the last century to have been less a march of progress than a slouch in the right direction.