In the early 1930s, network radio in the United States was dominated by two major companies: the National Broadcasting Company (NBC), formed in 1926, which operated two national networks, known as the NBC-Red and the NBC-Blue, plus the Columbia Broadcasting System (CBS), established in 1927. These two companies had subsequently signed affiliation agreements with almost all of the country's major radio stations, leaving limited program options for a few hundred remaining medium and small stations. This imbalance led to ongoing efforts to create a "third radio network", to help the left-out stations compete with the NBC and CBS programs.