On a quiet patch of former farmland in northeastern Louisiana, a fleet of excavators has leveled more than 2,000 acres of reddish clay earth. This is rural Richland Parish, once a floodplain tangled with meandering bayous and wild canebrake where black bears still wander and a quarter of the 20,000 residents live below the poverty line. Enter Meta—the sixth-largest company in the world by market cap. The tech giant is keen on making Richland home to its wildest AI aspirations—courtesy of a treme...