Dolan's legacy in cable broadcasting includes the 1972 launch of Home Box Office, later known as HBO, and founding Cablevision in 1973 and the American Movie Classics television station in 1984. He also launched News 12 in New York City, the first 24-hour cable channel for local news in the U.S., Newsday reported.

The Cleveland native, who dropped out of John Carroll University in suburban Cleveland, completed the sale of Cablevision to Altice, a European telecommunications and cable company, for $17.7 billion in June 2016.

Dolan, whose primary home was in Cove Neck Village on Long Island in New York, also held controlling stakes in companies that owned Madison Square Garden, Radio City Music Hall, the New York Knicks and the New York Rangers, Newsday reported.