Just a footnote here, this historical reference is very different in a lot of ways from Peter Maas account in his book. Look at the description for Mafia history in Wikipedia and you see where the historical references disagree. I tend to trust Wikipedia a little more about getting details right:
Italians did not invent organized crime, nor did they introduce it to this country. Indeed, when the first great wave of Italian immigrants arrived in the late 19th century, they found a flourishing underworld then primarily in the hands of the Irish and the Jews. Although just about every ethnic group has had a crack at it one time or another, including good old fashioned American families like the James boys. But what a very small number of these Italian newcomers -mostly from Naples, Calabria, and Sicily -did bring was a traditional clannish ness, contempt for legal authority, and a talent for organization that would eventually enable them to dominate racketeering in the US.
The first significant step in this direction occurred in the 1890s, when a gang of Sicilians gained control of the New Orleans waterfront. No cargo moved on or off the docks without their being paid tribute. Then the city’s Chief of Police, probing too energetically into their activities, was murdered. Nineteen members of their gang were brought to trial. The case against them, apparently airtight. But a dreary pattern, apparently so familiar today, was already being set. The best criminal lawyers in the country were hired and, helped no end by jury tampering, own acquittals for all but 3 of the defendants. The first time, however, the strategy backfired; after the verdict was in, an enraged crowd wound up lynching 11 of them and very nearly caused a diplomatic break between The Feds and Rome, Italy.
Such a bold penetration of the established underworld was exceptional in those days. The earliest organized Italian criminals in America, the Black Hand extortion rings, preyed almost exclusively on the vast majority of their decent, hardworking countrymen who had settled here. The name came from a crudely drawn black hand on the bottom of a letter demanding money from a victim and usually threatening the death or mutilation of his children if it was not paid. With the memory of the dreaded Mafia in Sicily or Neapolitan Camorra still fresh on their minds, distraught parents promptly forked over the cash. Black Hand extortionists promptly became a problem that in New York City a special police squad, led by Lt. Petrosino assigned to hunt them down. Furious that a handful of his own people was tarnishing the name of all Italians, he did his job too well; in 1909, while in Sicily to exchange criminal intelligence with local officials, he was shot in the back and killed.