After six years on local stations, national radio broadcaster Mutual network began airing the program. It carried the series on radio June 12, 1946, to April 2, 1947. It was sponsored by the Book-of-the-Month club, on Mutual. In summer 1946, Stone left Mutual "under agreement", airing the show on WQXR on Thursdays with the club sponsorship, and on Mutual without sponsorship. On May 20, Mutual filled his old time slot with "Books on Trial", a series sponsored by the Literary Guild, featuring a "prosecuting attorney and jury." Stone took the situation to court, alleging appropriation and effort to confuse. Stone lost in court, as State Supreme Court Justice Bernard Botein found no conflict of ideas.