Long before a host of the biggest players in Silicon Valley set their sights on creating a new city in Solano County, California, many billionaires thought they could start their own utopia. But one man, a retired AT&T executive from Georgia, has actually been able to do it—for better or for worse.

Oliver Porter, 85, is the architect of Sandy Springs, Georgia, a city of 108,000 people outside Atlanta that set off a wave of similar new towns when it incorporated in 2005. Porter has assisted in creating nearly a dozen new cities in Georgia and several others around the world. The legacy of that movement, which has improved services for some while icing out others, carries important lessons for those attempting to start their own private paradises today.