The Twentieth Century was an historical documentary series aired on Sunday afternoons on CBS owned-and-operated television stations. Each episode pertained to a particular subject of (necessarily) early-to-mid twentieth century history. Each program was constructed of actual historical film footage of the subject events, including much captured World War II footage. The programs were illuminated by the authoritative sound of Walter Cronkite's narration, done entirely off camera. These shows were immediately recognizable as a valuable compilation of photographic records of earlier times. In at least one major U.S. market, the program disappeared by 1961, being replaced in its time slot by Air Power (an earlier CBS Cronkite-narrated Wartime Documentary), just as The Twentieth Century replaced its CBS Sunday afternoon precursors, Gerald McBoing Boing cartoons, and before that, Omnibus with Alastair Cooke.