The Black Hand was the name of the extortion racket they performed. The mailing of a threatening letter. Eventually, it became at term to categorize a new type of criminal in Italian ghettos in America.

There was no real leadership or structure. Aside from when a bunch of Black Hand extortionists got together to form an operation. Most worked alone however.

In fact, most mafiosi that came over from Italy preyed upon and used Black Hand extortionist for their own ends. I also read that the Black Hand method was relatively unknown or obscure in Italy. Alot of former Black Handers became American mafia members later on in their careers tho.