Let me chime in, I really enjoyed this book as well. Read it on the way home from DL last February on the plane.
The murder history was good, but like EM and NA, the fascinating tale and real hook for me wa the whole story of the Worlds Fair.
I've never been to one, but I do wish I had been alive to go to the 1915 Pan Pacific here in SF the graceful and beautiful Palace of Fine Arts is the lone survivor and relic of that age. Or the Chicago Worlds Fair or the 1964 in New York which brough the Disney fans so much for Tomorrowland
Anyway, I digress, a good book and worth a read!