Roots of the B movie: 1920s: The B movie, whose roots trace to the silent film era, was a significant contributor to Hollywood's Golden Age of the 1930s and 1940s. As the Hollywood studios made the transition to sound film in the late 1920s, many independent exhibitors began adopting a new programming format: the double feature. The popularity of the twin bill required the production of relatively short, inexpensive movies to occupy the bottom half of the program. The double feature was the predominant presentation model at American theaters throughout the Golden Age, and B movies constituted the majority of Hollywood production during the period.
Rise of the double feature: 1930s:
The major companies upon which the Hollywood studio system was built had been resistant to the B-movie trend, but they soon adapted. All ultimately established "B units" to provide films for the expanding second-feature market. Block booking increasingly became standard practice: in order to get access to a studio's attractive A pictures, many theaters were obliged to rent the company's entire output for a season. With the B films rented at a flat fee (rather than the box office percentage basis of A films), rates could be set that essentially guaranteed the profitability of every B movie. Blind bidding, which grew in parallel with block booking, meant that the majors didn't have to worry over much about the quality of their B's—even when booking in less than seasonal blocks, exhibitors had to buy most pictures sight unseen.
Bs from major to minor: 1940s: By 1940, the average production cost of an American feature was $400,000, a negligible increase over ten years. A number of small Hollywood companies had folded around the turn of the decade, including the ambitious Grand National, but a new firm, Producers Releasing Corporation (PRC), emerged as third in the Poverty Row hierarchy behind Republic and Monogram. The double feature, never universal, was still the prevailing exhibition model: in 1941, 50 percent of theaters were double-billing exclusively, with additional numbers screening under the policy part-time.[45] In the early 1940s, legal pressure forced the studios to replace seasonal block booking with packages generally limited to five pictures (MGM carried on with blocks of twelve for a while). Restrictions were also placed on the majors' ability to enforce blind bidding.[46] These were crucial factors in the progressive shift by most of the Big Five over to A-film production, making the smaller studios even more important as B-movie suppliers.
B movies (Transition in the 1950s): The 1950s mark a significant change in the definition of the B movie. The transformation of the film industry due to court rulings that brought an end to many long-standing distribution practices as well as the challenge of television led to major changes in U.S. cinema at the exhibition level. These shifts signaled the eventual demise of the double feature that had defined much of the American moviegoing experience during Hollywood's Golden Age of the 1930s and 1940s. Even as the traditional bottom-of-the-bill second feature slowly disappeared, the term B movie was applied more broadly to the sort of inexpensive genre films that came out during the era, such as those produced to meet the demands of the burgeoning drive-in theater market.
The Exploitation Boom (60s to 70s): The 1960s and 1970s mark the golden age of the independent B movie, made outside of Hollywood's major film studios. As censorship pressures lifted in the early 1960s, the low-budget end of the American motion picture industry increasingly incorporated the sort of sexual and violent elements long associated with so-called exploitation films. The success of the B-studio exploitation movement had a significant effect on the strategies of the major studios during the 1970s.
B movies 1980's to present: Cinematic exhibition of the B movie, defined as a relatively low-cost genre film, has declined substantially from the early 1980s to the present. Spurred by the historic success of several big-budget movies with B-style themes beginning in the mid-1970s, the major Hollywood studios moved progressively into the production of A-grade films in genres that had long been low-budget territory. With the majors also adopting exploitation-derived methods of booking and marketing, B movies began to be squeezed out of the commercial arena. The advent of digital cinema in the new millennium appeared to open up new opportunities for the distribution of inexpensive genre movies.