where should I start?

The Jewish Mafia was very strong before being overwhelmed by the Italian Mafia

Arnold Rothstein (January 17, 1882 – November 6, 1928),nicknamed "the Brain","transformed organized crime from a thuggish activity by hoodlums into a big business, run like a corporation, with himself at the top." Rothstein was allegedly responsible for fixing the 1919 World Series and was the master of Lucky Luciano.

Meyer Lansky (July 4, 1902 – January 15, 1983) friend of Luciano and up to the end he was one of the most powerful mafia associates

Murder, Inc. Jewish Members

Louis "Lepke" Buchalter - original head of Murder, Inc.

Benjamin "Bugsy" Siegel the men that created Las Vegas
Abe "Kid Twist" Reles
Martin "Buggsy" Goldstein
Harry "Pittsburgh Phil" Strauss
Mendy Weiss
Hyman "Curly" Holtz
Jacob "Gurrah" Shapiro
Louis Cohen
Louis "Shadow" Kravitz
Philip "Little Farvel" Kovolick
Samuel "Red" Levine

Dutch Schultz (August 6, 1901 – October 24, 1935) a prohibition boss,killed by the mafia because his violent nature and because asked the ok for kill prosecutor dewey.

Meyer Harris "Mickey" Cohen (September 4, 1913 – July 29, 1976) was a gangster based in Los Angeles and part of the Jewish Mafia, and also had strong ties to the American Mafia from the 1930s through 1960s.