That is why governments and the private sector have invested in them, and why they were often created on gargantuan scales. They were the most effective peaceable way to wage war.
World’s Fairs haven’t enjoyed an even history since the founding event, The Great Exhibition of the Works and Industries of All Nations held in London in 1851. There were two periods in which the medium took on a frequency and a drama that effectively made them into golden ages: the fin de siècle, and the 1960s.
During the first, beginning with the Philadelphia Exposition of 1876, there was an epic-scale Expo somewhere in the world every few years through to the First World War. In some years, such as 1888 (Glasgow, Barcelona, Melbourne), or 1906 (Toronto, Marseilles, Bucharest, Christchurch) there was more than one. Every one of these was spectacularly ambitious and, judged by their own criteria, highly successful. Each one would have made the Millennium Dome, the last feeble and ill-fated attempt at the medium in England in 2000, look like a village fête.
Major cities, such as Paris, Chicago, Philadelphia, Barcelona, Brussels, San Francisco, Buffalo, Turin and St Louis were transformed by them, and as this list shows, at that point Expo was basically a creature of Europe and North America. The second golden age, boasting far fewer but truly spectacular events, was the 1960s. The sequence then was Brussels (1958), Seattle (1962), New York (1964), Montreal (1967), and Osaka (1970). The five shared a stylistic, artistic, technological, and intellectual consistency that helped shape and define that brilliant short run of years. One of the more remarkable statistics is that at 51 million visitors, more than double the population of Canada attended the Montreal Expo.
These two golden ages, contained Expos that in so many ways shaped, influenced and reflected the culture and ethos of the societies they decorated.