In the 19th century many American urban centers become quite densely built up with all manners of buildings. These urban centers were also prone to fire. A number of cities experienced major fires that wiped out large swaths of what had been built. So they got rebuilt with more modern structures.
Most of the terrible modernism comes from the postwar era, when city planners would drive concrete highways through minority neighborhoods and bulldoze "slums" for modernist housing projects that were supposed to cure society's ills.
I’ll take “what is Scollay Square “ for $500. The point being that it’s not a linear progression. And we won’t mention what two world wars did to cities in Europe.
