The oldest broadcasting network in the United States, the National Broadcasting Company (NBC) came into being on November 15, 1926, with a gala four-hour radio program originating from the ballroom of the Waldorf-Astoria Hotel in New York City. NBC was the joint effort of three pioneers in mass communications: Radio Corporation of America (RCA; nowRCA Corporation), American Telephone and Telegraph (now AT&T Corporation), and Westinghouse Electric Corporation.