Show business, for fascinating and historically complicated reasons, has always held great appeal to Americans of the Jewish faith. The Boston-New York establishment around the beginning of the last century was bigoted and snobbish, and the go-getters who started the film business – Louis B. Mayer, Adolph Zukor, Jack Warner, men like that – weren’t welcome in the white shoe law firms and Episcopalian investment banks on the east coast. So they did what ambitious young men always do: they headed west...