Looking back at the architecture and urban design of the 1800s offers some answers, but a missing piece in the story is found in Victorian utopian literature. The replacement of cities with high-tech suburbs was repeatedly imagined and breathlessly described in the socialist dreams and science-fiction fantasies of dozens of British and American authors. Some of these visionaries -- such as Robert Owen, Edward Bulwer-Lytton, Edward Bellamy, William Morris, Ebenezer Howard, and H.G. Wells -- are enduringly famous, while others were street vendors or amateur chemists who have been all but forgotten. Together, they fashioned strange and beautiful imaginary worlds built of synthetic gemstones, lacy metal colonnades, and unbreakable glass, staffed by robotic servants and teeming with flying carriages. As different as their futuristic visions could be, however, most of them were unified by a single, desperate plea: for humanity to have a future worth living, we must abandon our smoky, poor, chaotic Babylonian cities for a life in shimmering gardens.