The Jews who founded Hollywood — and make no mistake, the big studio heads were overwhelmingly Jewish — shared several things: ambition, creative vision and killer business instincts. But more than anything else, the men who were the driving forces behind Paramount, 20th Century Fox, Warner Brothers, Universal, Columbia and Metro-Goldwyn-Mayer shared a very 20th-century sense of being Jewish in America. They were assimilationists who considered themselves American above all else and who molded Hollywood to reflect and shape their American ideals. “Above all things, they wanted to be regarded as Americans, not Jews,” Neal Gabler wrote in his definitive...