Olive Oil War
Working with colleagues Al Hats and Richie Gatto, the Clemenza regime was activated during the Olive Oil War with Giuseppe Mariposa. When Richie Gatto was killed and Vito Corleone was wounded by a gang of Irishmen, Clemenza had Mancini and Al Hats pick up Corr Gibson and take him to be killed.
He had one daughter, Lucy, who went on to become the mistress of Don Vito Corleone’s eldest son, Sonny Corleone. Lucy would have one child by him, Jimmy’s grandson, the future Don of the Corleone family, Vincent Mancini.
Little is known about Jimmy Mancini following the Olive Oil War, as he does not appear and is not mentioned during the Five Families War. It is presumed he was died at some point before 1945.