having "put Seattle on the map" as "an aerospace city", a major theme of the fair was to show that "the United States was not really 'behind' the Soviet Union in the realms of science and space". As a result, the themes of space, science, and the future completely trumped the earlier conception of a "Festival of the [American] West".

In June 1960, the Bureau International des Expositions (BIE) certified Century 21 as a world's fair. Project manager Ewen Dingwall went to Moscow