ProgressCityUSA has an (extensive) article about the designing and building of Epcot Center. The date for most of this is actually the mid-seventies, but its still got that great retrofuturistic flair.
PCOT Center’s path from concept to execution was, in so many ways, far more tortured than most Disney fans know. Far from a merely difficult transition from Walt’s concept for a futuristic city to a permanent World’s Fair (or, as modern revisionists would have it, a straight shot from Walt’s mind to the park that opened in 1982), EPCOT’s development occupied the full span of the 1970s and in that time took a number of different forms. EPCOT, in one form or another, was announced on several different occasions – often with great fanfare. But as disjointed as this development process might seem, in retrospect it follows a clear evolution, with concepts changing and merging but core themes remaining throughout.