The leap from ethnic pride to gay pride was not a large one. The specifics of each project are dreamed up by local groups, so they tend to highlight the diversity of the city, from the Grecian pillars in Greek Town to the Puerto Rican flags in Humboldt Park.
Why is the first explicit recognition of a gay district in Chicago, and not San Francisco or New York? It seems to have followed naturally from a Chicago neighbourhood restoration scheme that has spent $2 billion on 20 different projects since 1993.