World's fairs originated in the French tradition of national exhibitions, a tradition that culminated with the French Industrial Exposition of 1844 held in Paris. This fair was followed by other national exhibitions in continental Europe and the United Kingdom.
The best-known 'first World Expo' was held in The Crystal Palace in Hyde Park, London, United Kingdom, in 1851, under the title "Great Exhibition of the Works of Industry of All Nations". The Great Exhibition, as it is often called, was an idea of Prince Albert, Queen Victoria's husband, and is usually considered to be the first international exhibition of manufactured products. It influenced the development of several aspects of society, including art-and-design education, international trade and relations, and tourism. These events have resulted in a remarkable form of Prince Albert's life history, one that continues to be reflected in London architecture in a number of ways, including in the Albert Memorial later erected to the Prince. This expo was the most obvious precedent for the many international exhibitions, later called world's fairs, that have continued to be held to the present time.
Since their inception in 1851, the character of World Expos has evolved. Three eras can be distinguished: the era of industrialization, the era of cultural exchange, and the era of nation branding.
The first era could be called the era of "industrialization" and covered, roughly, the period from 1800 to 1938. In these days, world expositions were especially focused on trade, and were famous for the display of technological inventions and advancements. World expositions were the platforms where the state-of-the-art in science and technology from around the world were brought together. The world expositions of 1851 London, 1853 New York, 1862 London, 1876 Philadelphia, 1889 Paris, 1893 Chicago, 1897 Brussels, 1900 Paris, 1901 Buffalo, 1904 St. Louis, 1915 San Francisco, and 1933–34 Chicago were landmarks in this respect. Inventions such as the telephone were first presented during this era. An important part of the image of world's fairs stems from this first era.
Cultural exchange (1939–1987)
The 1939–40 New York World's Fair diverged from the original focus of the world's fair expositions. From then on, world's fairs adopted specific cultural themes; they forecast a better future for society. Technological innovations were no longer the primary exhibits at fairs. The theme of the 1939 fair was "Building the World of Tomorrow"; at the 1964–65 New York World's Fair, it was "Peace Through Understanding"; at the 1967 International and Universal Exposition in Montreal, it was "Man and His World". The fairs encouraged effective intercultural communication for the exchange of innovation.
The 1967 International and Universal Exposition in Montreal was promoted under the name Expo 67. Event organizers retired the term world's fair in favor of Expo. (The Montreal Expos, a former Major League Baseball team, was named for the 1967 fair.)
Nation branding (1988–present)
From World Expo 88 in Brisbane onwards, countries started to use expos more widely and more strongly as a platform to improve their national images through their pavilions. Finland, Japan, Canada, France, and Spain are cases in point. A large study by Tjaco Walvis called "Expo 2000 Hanover in Numbers" showed that improving national image was the primary participation goal for 73% of the countries at Expo 2000. In a world where a strong national image is a key asset, pavilions became advertising campaigns, and the Expo a vehicle for "nation branding". Apart from cultural and symbolic reasons, organizing countries (and the cities and regions hosting them) also utilize the world exposition to brand themselves. According to branding expert Wally Olins, Spain used Expo '92 and the 1992 Summer Olympics in Barcelona in the same year to underline its new position as a modern and democratic country and present itself as a prominent member of the European Union and the global community.
At Expo 2000 Hannover, where countries created their own architecture, the average pavilion investment was about €12 million. Given these costs, governments are sometimes hesitant to participate, because benefits are often assumed not to outweigh the costs. Tangible effects are difficult to measure, but an independent study for the Dutch pavilion at Expo 2000 estimated that the pavilion (which cost around €35 million) generated around €350 million of potential revenues for the Dutch economy. It also identified several key success factors for world-exposition pavilions in general.