Actually, the Mafia has worked with other ethnic groups going all the way back to the Irish and Jewish gangsters in the early 20th century. But it's true that there was about a 50 year window, between the 1930's and 1980's, after the Irish and Jews had largely been supplanted by the Italians and before the rise of the South American drug cartels, Asian and Russian OC groups, etc. where the Mafia held the most sway.

In the late 1970's the New York Housing Authority planned to replace millions of windows throughout the city in order to save money on heating. Over the period of 12 years, from 1978 to 1990, the Genovese, Lucchese, Gambino, and Colombo families, through their control of about a dozen windows companies and Local 580 of the Architectural and Ornamental Ironworkers Union, rigged about 75% of the bids - or about $142 million out of $191 million - to go to mob companies. Any unaffiliated companies who wanted to receive a contract had to pay a mob tax of $2 a window. In other words, it was structured much like the mob's concrete club was. The Genovese family was the main player in the scam but had to bring in the Lucchese family because it directly controlled Local 580. And once the Gambino and Colombo families saw the money involved, they became involved as well. As usual, the Bonanno family was left out of this joint family racket. Genovese family associate Peter Savino was the initial lynchpin in the scam but later became a governement witness.

Among those ultimately charged in the case included:

Venaro "Benny Eggs" Mangano (Genovese underboss)
Dominick "Baldy Dom" Canterino (Genovese captain)
Joseph Zito (Genovese captain)
Peter "Fat Pete" Chiodo (Lucchese captain)
Joseph "Joe Cakes" Marion (Lucchese associate)
Benedetto "Benny" Aloi (Colombo consigliere)
Dennis DeLucia (Colombo soldier)
Vincent "Three Fingers" Ricciardo (Colombo associate)
Peter Gotti (Gambino captain)
Caesar Gurino (Gambino associate)
Thomas McGowan (Local 580 business agent)