Abt (300) World's Fair Covers 1933 Chicago to 1992 Spain; sorted by fair, a few foreign, diff cachets & themes, FDC for commem stamps, special cachets or cancels, incl New York '39 & '64, 1958 Brussels, 1967 Canada, Hemisfair, 1974 Spokane, 1984 Louisiana, others; gen F-VF