The Chicago World's Fair was held in 1893 to celebrate the 400th year anniversary of Columbus' arrival on North America. It was an amazing feat, covering more than 600 acres with nearly 200 new buildings built solely for the purpose of the fair along with fabricated canals and lagoons. Over 27 Million people attended.
As much as I wish I had been able to attend, I do get some satisfaction knowing I can experience a small part of what it must have been like by just getting on a Ferris Wheel.
The Ferris wheel at the World's Columbian Exposition, the first of it's kind:

To put into perspective how tall the wheel was this illustration compares it to other landmarks:

The wheel wasn't the two-seater sporty version we see these days. In this (beautiful) photo you can see one of the cars across from the photographer and get an idea of the spectacle of the wheel. Something grand, not intimate like the ones today.

I haven't been able to think of a comparable event that has (or could) take place today, but if you can please let me know.