At its peak, Main Line Broadcasting owned 19 radio stations in four markets in the United States.
Main Line was backed by the Arlington Capital Group, a private equity company.
Main Line's first acquisition was Dame Broadcasting's 5-station group in Hagerstown, Maryland in August 2005.
In December 2005, Main Line purchased four stations from MainQuad Broadcasting in the Richmond, Virginia market.
In May 2007, Main Line doubled in size with the purchase of ten stations from Radio One in the Louisville, Kentucky and Dayton, Ohio markets.