@Nicky from Tempa
By the way Frauenfels Ndrina is completely independent.

I see your point. So i give you right if we talk about a new family. But American Mafia exist there. So the need only new Blood and i think there are more then enough. So 5 or 10 guys (without arrest) are more than enough. If it necessary got to New York and take some guys from there. Mafia is a elite thing not a mass organization. But they die out. And again it is not enough to say " of course they had no neighborhood.

Another thing is American Mafia can change the rules. So they don't need to ask Palermo. In fact LA don't need ask New York for new rules about new members. They can give mixed blood made member status or work with non-italians( like Chicago). So my guess is they hadn't enough business on the run. Not enough White dollar connection. So young guys don't need them. After a while they lost muscles and cannot protect his business and members get older. So they disappear. (exception is Tommy Gambino this guy is a mystery for me).

Another scenario is LA mafia never (or only Dragna) exist as a independent group and chicago and Cleveland was not interested to the refresh the group in the late 90's. So only Gambino with his New York connection "survive".

For SF i think is the other way around. They was verry successful and lost the interest in street/crime stuff.