Calling the idea audacious is almost criminal understatement. Imagine it: A pristine new megacity rising from the hills, bluffs, and fields of Northwest Alabama, an urban center ten times the size of Manhattan but unlike it and every other city in most every way. Its architects envisioned a unified but decentralized constellation of miniature farms and villages stretching seventy-five miles along the Tennessee River, a shining city atop not one hill but hundreds. Most of
