“The property’s previous owner was Formosa, a plastics and petrochemical giant, which in 1991 planned to build a $700 million plant for manufacturing rayon on its nearly 2,000 acres. Preservationists and environmentalists balked. Looking for avenues of appeasement, Formosa commissioned an exhaustive survey of the grounds, with the idea that the most historic sections would be turned into a token museum of Creole culture while a majority of the rest would be razed to make way for the factory. In the end, it was wasted money and effort: The opposition remained vigilant, rayon was going out of fashion, the Whitney went back on the market and Cummings inherited the eight-volume study with the purchase. “Thanks to Formosa, I knew more about my plantation than anyone else around here — maybe more than any plantation in America outside of Monticello,” said Cummings, a litigator accustomed to teasing secrets from dense paperwork. “A lot of what was in there was about the architecture and artifacts, but you started to see the story of slavery. You saw it in terms of who built what.””