The World Expo 2010 in Shanghai, China, opened this month and expects to attract 70 million visitors.
If you are not going to China, you can still visit the World Expos of the past, here in the National Archives.
Since the 1876 exposition in Philadelphia, the United States has hosted over a dozen expos. The growing concern for the environment in the early 1970s (the first Earth Day in 1970, establishment of the EPA in 1971) made it appropriate that the theme of Expo 74 in Spokane was “Celebrating Tomorrow’s Fresh New Environment.”
One of the EPA’s DOCUMERICA photographers, Charles O’Rear, took pictures of the preparations for the Spokane Expo, and several of these are online in the National Archives Archival Research Catalog.