[galleyfox]

Most Europeans on vacation in the U.S. don't particularly care to visit our cities at all. Maybe New York and Los Angeles because they appear in the movies, but for the most part they much prefer the National Parks, and the Midwest just drew the shortest short stick on that front.

Chicago is just so isolated from the other major metros like no other U.S. city. International tourists have trouble fitting it into an itinerary. But that isolation makes Chicago a monster when it comes to domestic tourism, second only to Orlando by some measures. It has no regional competition.
Speaking to my European relatives, it seems that Chicago is developing a reputation abroad as the "authentic" American cultural experience. They come to America wanting to see the famous sights, but also to see the lifestyle and people that they remember from old Westerns and thrillers and noir films, and they're not finding too much of it in New York, LA or Las Vegas anymore.