Carlos "The Little Man" Marcello was the boss of the New Orleans crime family - the first Mafia family in the US - from 1947 until 1983/1990. Once the undisputed crime boss from Florida to Texas, he is believed to have played a significant role in the assassination of John F. Kennedy (although never proven).
Marcello lived in this home until the 1960s when he moved to a more blue-collar area of the city because he wasn't willing to cope with the "aristocrats". He kept the house, though, and returned at the end of his life. Marcello died here in 1993, at the age of 83.