From Wikipedia,
"The apparently first pirate TV station in the US was Lanesville TV, active between 1972-1977 and operated by the counter-cultural video collective the Videofreex from Lanesville, NY. Another documented pirate TV station in the 1970s was Lucky 7, which broadcast for a single weekend in April 1978 from Syracuse, New York."
https://en.wikipedia.org/wiki/Pirate_television