World's Fair souvenirs from all of the fairs are collected. The first fair was the Great Exhibition of 1851 in London. The term "world's fair" was used to refer to these events until Expo 67 in Montreal, when the term "expo" became popular. Some other important exhibitions and fairs include Philadelphia, 1876 (Centennial); Chicago, 1893 (World's Columbian); Buffalo, 1901 (Pan-American); St. Louis, 1904 (Louisiana Purchase); Portland, 1905 (Lewis & Clark Centennial Exposition); San Francisco, 1915 (Panama-Pacific); Paris (International Exposition of Modern Decorative and Industrial Arts), 1925; Philadelphia, 1926 (Sesquicentennial); Chicago, 1933 (Century of Progress); Cleveland, 1936 (Great Lakes); San Francisco, 1939 (Golden Gate International); New York, 1939 (World of Tomorrow); Seattle, 1962 (Century 21); New York, 1964; Montreal, 1967; Knoxville (Energy Turns the World) 1982; New Orleans, 1984; Tsukuba, Japan, 1985; Vancouver, B.C., 1986; Brisbane, Australia, 1988; Seville, Spain, 1992; Genoa, Italy, 1992; Seoul, Korea, 1993; Lisbon, Portugal, 1998; Hanover, Germany, 2000; Shanghai, China, 2010; and Milan, Italy, 2015. Memorabilia of fairs include directories, pictures, fabrics, ceramics, etc. Memorabilia from other similar celebrations may be listed in the Souvenir category.