I've often been asked "when did annual passes" first become available. Well according to this 1984 brochure, 1984 was the "first time ever" an annual passport was available.
The first year of the annual passport it was available ONLY to Magic Kingdom Club members, the following year it would be available to "normal" guests for a higher price.
$65 seems really cheap even in 1984 dollars. Its was about $14 for a one day passport, so this new annual pass would pay for its self after just a few visits (whoa, I should like a Disney shill!)... It would increase to $75 in 1985 ($85 for non club members).