You would need to go back to McCullough, Pitts and von Neumann in the 1940s if you wanted to talk about where it really got started.

The 1970s were a long, dark AI winter, thanks to FUD spread by Minsky and Papert. A lot of recent work could have been done back then despite the lack of good hardware, as seen in the other HN story where the guy trained a transformer on a PDP-11. But the whole field was radioactive after their book came out.