Sigh. I finally found a list, under "exposition." Details to follow:
The first modern international exposition was the Crystal Palace Exhibition in London in 1851, also apparently known as the International Exhibition.
Otis premiered his elevator at the Crystal Palace Exposition in New York City in 1854 (presumably an imitator) (Good story -- he had himself hauled up in the cage and then ordered his assistants to cut the ropes. The crowd gasped! He stayed in place, unhurt.)
Other famous expos include:
The Paris Exhibition, 1802, exhibitors including J.E. Montgolfier, the balloonist, and J. M. Jacquard, the loom inventer (and precursor, in case you didn't know this, which you did, of the Hollerith card and thence those punch cards you used in college.)
New York and Dublin, 1853
Melbourne and Munich, 1854
Paris 1855, in the Palais d'Industrie, which was pulled down for the 1900 exhibition. (5,162,330 visitors!)
World's Fair in London and Exposition in Rome, 1862
The Paris International Exposition, 1867-- 41 acres, 6,805,969 visitors.
The Centennial Exposition, Philadelphia, 1876, 48 1/2 acres, 9,892,625 visitors; big machinery display powered by a 1600-hp Corliss engine
Paris, 1878 Sydney, 1878 Melbourne 1879 Brussels 1880
Centennial Exposition, Paris, 1889 (Eiffel Tower) Centenary of the French Revolution, which "...did not commend it to several European governments....which were conspicuous by their absence." e.g. Germany, Sweden
1892 Exhibition of electrical appliances at the Crystal Palace, London
World's Columbian Exposition, Chicago, 1893; construction of an elevated electric railway. Canals had steamships; 21,477,212 visitors, 200 acres.
Paris Exhposition of 1900, 39,000,000 visitors, 549 acres total.
New York, 1901
Louisiana Purchase Exposition, St. Louis, 1904 ("Meet me in St. Louis, Louis, meet me at the fair....")
Liege, 1905, Milan 1906, Dublin 1907 London (Franco-British) 1908
<at this point the 11th Britannica opines, "And it might well be thought that the evolution of this type of public show had reached its limits." A World War later, expositions were back:)
British Empire Exhibition at Wembley, 1924-25
Century of Progress Exposition at Chicago, 1933-34
Golden Gate International Exposition, San Francisco, 1939-40
New York World's Fair, 1939 (Trylon and perisphere)
(another world war)
Brussels World's Fair, 1958
and the 1962 exposition at Seattle, Expo 67 in Montreal, Expo 70 in Osaka, Japan, and Expo 74 in Spokane Washington.
Aha! There is a "Bureau of International Expositions" in Paris which regulates and sanctions world's fairs and international expositions. I think you need to be in contact with them.