Complex sentence: His natal city Cincinnati was an important center for radio in the 1920s; the nation's largest radio sponsor, Procter & Gamble, and one of its most powerful radio stations, WLW, were both based there.
Split into simpler sentences: His natal city Cincinnati was an important center for radio in the 1920s. The nation's largest radio sponsor, Procter & Gamble, and one of its most powerful radio stations, WLW, were based there.