Short subject films have a long history in American cinemas. These could be anywhere from 2 to 40 minutes long and were used as a "filler" in a picture show that would include a cartoon, a newsreel, possibly a serial and a short before launching into the feature film. Shorts could tackle any topic of interest: an unusual travelogue, a comedy, musical revues, sports, nature or popular vaudeville acts. With the advent of sound-on-film in the mid-to-late 1920s, makers of earlier silent short subjects began experimenting with the short films, using them as a testing ground for the use of sound in feature movies. After the Second World War, and the rising popularity of television, short subject films became far too expensive to produce and they had mostly disappeared from the screens by the late 1950s. This encyclopedia offers comprehensive listings of American short subject films from the 1920s through the 1950s.