By the late fifties or so Lanksy was pretty much the only major Jewish-American crime boss still extant. Gangsters such as Buchalter, Shapiro, Schultz, Siegel, Zwillman, Rothstein, King Solomon and others were either dead or imprisoned. The Gambino and Lucchese families (and others) had taken over NY garment center rackets that had previously been the purview of people like Buchalter. The public face of US organized crime had become stereotypically Italian-American.

Why did this happen?
Why didn't Jewish organized crime reproduce itself in stable organizations like the Italian "families"?
Would the history of OC in America be any different had Buchalter and others survived to the sixties/seventies etc..

Seems like you're talking about the Ashkenazi Jews (Central/Eastern Europe). Israeli and Russian Jew mobs are very much alive in America. Anyways back on topic.

I think the reason that the LCN has survived is due to two things. A longstand tradition and rigid heirarchy with a certain rules and ethnic and cultural identity.

The Jews assimilated into mainstream American culture much quicker then their Italian counterparts. And since organized crime and gang activity in general has it's origin in financially destitute alienated immigrant populations, as they melded into the American system they hadn't much use for the tool of organized crime.

The Irish did the same thing, albeit slower in the Irish neighborhoods of Boston, NYC and Philly. Permeating and infiltrating the system as politicians, cops, clergy etc etc. As they achieved positions of power the way of organized crime as a way to move up in the world was no longer as necessary. Simply had more options.

Today, most Jews of that wave become prominent businessmen, and achieved legitimate success. Although there have of course been poor Jews in the big cities who have joined the LCN over time (Chris Rosenberg comes to mind). But nothing in the vast numbers of the 20s and 30, at least not large enough to have their own network (aka the Jewish Mob).

On another not tho, Israelis are some bad motherfuckers hehe

The Jewish mobster experience was essentially a two generation phenomenon. The first generation of your Rothsteins, Zeligs and Solomons gained significant power but it was the second generation of Lanksys,Lepkes, Siegels,and Dalitzs that took it to another level. By the late 1950s, really only Meyer Lanksy, Moe Dalitz and Mickey Cohen were the only major players left. The most logical reason that can be seen is social mobility, with a footnote that Jewish kids were encouraged to move up in society more than Italian or Irish kids who's families encouraged economic stability over social mobility.

Interesting social note.
Like your post man

kosher nostra !!

AmericanCrime already said it.
The Israeli Mafia ( Mizrahi Jews ) is very big and the Russian Mafia also has a lot of Russian/Ukrainian/Belarusian members of Jewish ethnicity.