In the 1920s and 1930s Jewish gangsters united to form large-scale businesses that dealt in prostitution, extortion, drugs and bootlegging. They also went into the assassination business to ensure that they remained in power throughout the major cities of the United States. Some Jewish gangsters united with their Italian contemporaries and functioned under Mafia rules. By the Second World War, battles over turf and arrests by the Federal Bureau of Investigation had convinced many of these people to go legitimate and they moved to Las Vegas and went into the entertainment business. 

What is interesting is that some of the Jewish mobsters, such as David Berman, fought valiantly during the war or supported the Allied effort in other ways such as protecting the docks and ports where they remained in power.

Meyer Lansky, Mob Accountant

Samuel Gompers, founder of AFL

John L. Lewis, Founder of CIO

Murder, Inc.

Samuel Red Levine

Moe Sedway

Bo Weimberg

Arnold Rothstein

Louis Buchalter

Jewish-American organized crime emerged within the American Jewish community during the late 19th and early 20th centuries. It has been referred to variously in media and popular culture as the Jewish Mob, Jewish Mafia, Kosher Mafia, Kosher Nostra,[1][2] or Undzer Shtik (Yiddish: אונדזער שטיק‎).[a][2] The last two of these terms are direct references to the Italian Cosa Nostra; the former is a play on the word kosher, referring to Jewish dietary laws; while the latter is a direct translation of the Italian phrase Cosa Nostra (Italian for "our thing") into Yiddish, which was at the time the predominant language of the Jewish diaspora in the United States.

Meyer Lansky(born Meier Suchowlański;[2] July 4, 1902 – January 15, 1983), known as the "Mob's Accountant", was an American[3] major organizedcrime figure who, along with his associate Charles "Lucky" Luciano, was instrumental in the development of the National Crime Syndicate in the United States.[4]