In 1893 Chicago held a huge fair, the World's Columbian Exposition, ostensibly to celebrate the 400th anniversary of Columbus's arrival in the Americas but in reality to bind together the city's squabbling immigrants and fractious social groups with a bit of cultural adhesive.
The classification came about thanks to Napoleon III, who ordered a group of wine brokers to come up with a list of the best Bordeaux in time for the Paris Exposition, a sort of national trade fair.
The exposition's buildings turned out to be mostly neo-classical pastiche, but the fair did bequeath a sense of cultural pride and, more tangibly, the makings of a new home for the Art Institute.