It was my understanding that infra construction everywhere was pretty messy and bloody 100 years ago? It's probably no coincidence that the heyday of subway c

It was my understanding that infra construction everywhere was pretty messy and bloody 100 years ago? It's probably no coincidence that the heyday of subway construction in NYC was over not long after the immigration ban of 1924 removed a source of plentiful cheap labor. (Of course, the Great depression not withstanding new deal subsidizing of IND lines, general impossibility of private transportation to stay profitable, and then WWII diversion of the production obscures this.)