"B" movies were low-budget productions made during the era of the motion picture–studio system, mainly during the 1930s and 1940s. During this period of time, large movie studios dominated the production and distribution of all movies. There really is no equivalent to the "B" movie today, although low-budget, independent movies such as The Blair Witch Project (1999) could be considered similar.

During the studio-system era, the motion-picture studios not only made the pictures but also owned the theaters where they were shown. Usually the theaters of the time would show a cartoon, a newsreel of the current headlines, and two feature movies. One was the feature or "A" picture, such as Gone with the Wind (see entry under 1930s—Film and Theater in volume 2). The other feature movie was the "B" picture, a shorter, cheaper film that supported the main feature.

The...