Why do we have clearly divided zoned areas for work and residential again? What era did that start? If you really, really want to know: https://www.amazon.com/

Why do we have clearly divided zoned areas for work and residential again? What era did that start? If you really, really want to know: https://www.amazon.com/Zoning-Rules-Economics-Land-Regulation/dp/155844288X?ie=UTF8&tag=thstsst-20&linkCode=as2&camp=1789&creative=390957 https://www.amazon.com/Zoning-Rules-Economics-Land-Regulatio...