The American cinema in the 1940s was an industry at war, fighting monumental battles at home and overseas, both on-screen and off. Chief among those battles, of course, was World War II, the defining event of the decade for the movie industry and for the nation at large. Never before had the interests of the nation and the industry been so closely aligned, and never had its status as a national cinema been so vital. The industry's "conversion to war production" from 1942 to 1945 was eminently successful, as Hollywood enjoyed what may have been its finest hour as a social institution and a cultural force. The war also ignited a five-year economic boom, pushing box-office revenues and film studio profits to record levels.

While World War II was the signal event of the decade, however, Hollywood's fiercest and most significant battles were waged on the domestic front-battles with the...