Peppino, there's a great deal of BS about Siegel and Dragna, most of it perpetuated by Mickey Cohen, a small timer and a publicity hound. Dragna's main racket was shaking down bookies. Siegel went West to expand gambling, which he saw as underdeveloped by Dragna and Tony "The Admiral" Cornero, who ran gambling ships out of LA harbor. Siegel and Dragna were in conflict, but they found a way to cooperate by building the Trans Continental Racing Wire, with NY's help, which the bookies needed and which brought in an enormous amount of revenue.

No one was ever arrested, much less tried and convicted, in Siegel's murder. Some writers think Dragna was responsible, out of resentment of Siegel. I think Siegel was murdered on NY's orders because of the Flamingo fiasco.