I've been to quite a few World's Fairs. I went to the one in Seattle in 1961 with my parents. It was very nice. I loved the Space Needle. I was up on top of it again last year. Why does it seem so much smaller than when I was a kid? The fair was actually not all that large, but Seattle is so beautiful we saw a lot of the local scenery.
We also did the 64' World Fair in Flushing, NY. I liked that one better. Maybe cause' I was older? But I loved the UniRoyal ferris wheel (a big tire) and I saw the introduction of the 64 1/2 Ford Mustang! Whhhheee!
I also went to the fair in New Orleans where I almost crapped in my pants on that gondola ride over the Mississippi. We didn't get to see the entire thing cause' it was too damned hot! We went in July and came prepared. cotton clothing, shorts, bottles of Shower to Shower dust, and we still were drenched to our underwear in sweat the entire time we were there. And most all of the exhibitions were air conditioned!
But we did get to see George Burns perform and the exhibit halls were very nice.
When was the last one in the U.S.? Wasn't it that one in Knoxville, KY where nobody came? I remember flying over it and seeing it from the air, but never went.