At the time, he was selling special programming to hotels through his Teleguide service, while cable television was taking off in rural areas.
In 1964 Dolan made a deal with New York to wire some Manhattan buildings with cable and a few years later, hoping to attract viewers, he made a deal to show the Knicks and Rangers play-offs on cable, according to Variety.
He then went on to create Home Box Office for movies, and then sold both his cable service and HBO to build up Cablevision, which ended up providing television and internet to households across the north-eastern United States.
In 2015, the Dolan family sold Cablevision to European company Altice for nearly $18bn (£14.3bn).
By then Dolan’s son James was running what the New York Times called the family’s empire.
And the Dolans had become “the family that New Yorkers often loved to hate”, according to the New York Times, over frustration over the Knicks’ performance and fights with networks over their programming that had threatened to keep customers from watching the Academy Awards and the World Series.
Dolan was worth $5.4bn (£4.3bn) at the time of his death, according to Forbes.