Delphine McCarty

Marie Delphine Macarty or MacCarthy (March 19, 1787 – December 7, 1849), more commonly known as Madame Blanque or, after her third marriage, as Madame LaLaurie, was a New Orleans socialite who tortured and murdered enslaved people in her household.
Born during the Spanish colonial period, LaLaurie married three times in Louisiana and was twice widowed. She maintained her position in New Orleans society until April 10, 1834, when rescuers responded to a fire at her Royal Street mansion. They discovered bound slaves in her attic who showed evidence of cruel, violent abuse over a long period. LaLaurie's house was subsequently sacked by an outraged mob of New Orleans citizens. She escaped to France with her family, and was never brought to justice.
The mansion traditionally held to be LaLaurie's is a landmark in the French Quarter, in part because of its history and for its architectural significance. However, her house was burned by the mob, and the "LaLaurie Mansion" at 1140 Royal Street was in fact rebuilt after her departure from New Orleans.

Biography fallback source: Wikipedia