Fairly often and I'm not from Chicago. If I could time travel, 1893 would be on my short list of destinations because of the Chicago world fair.

Another one would be 1851, the year of the first world fair in London. The old fairs would already be awesome for a modern visitor, but I can't imagine what the people living then must have felt, seeing things like electricity for the first time.

I can't visit them, but I did at least dedicate 2 chapters of my game to the 1851 one: https://store.steampowered.com/app/3040110/Outsider/