April 20, 1872 (details from Chapter 3 of Deep Water):
New Orleans Mafia leader Joseph "Peppino" Agnello was shot to death during a gunfight at the Picayune Tier, a preferred docking spot for Sicilian lugger vessels and ships involved in the fruit trade.
Successor to the leadership of his murdered brother Raffaele's underworld organization, Joseph Agnello was wounded in several assassination attempts from 1870 to 1872. More than once, he was reported to be near death but miraculously recovered.
He finally met his end after gunmen cornered him on the dock. Agnello tried to escape by jumping aboard the moored schooner Mischief, but after some exchange of gunfire a large-caliber horse-pistol slug fired by Joseph Maressa struck him in the midsection.
The slug passed through Agnello's body and ripped a gaping hole in his back.
The murder of Joseph Agnello apparently concluded a four-year New Orleans underworld civil war between the Agnello-dominated Palermo-born Mafiosi and a rival group composed of crime figures from Messina and Trapani.