nyc was first city in u.s. to enact zoning law in 1916, virtual unanimity existed among real estate interests that zoning would be useful tool for protecting valuable land, principal theme was that zoning kept land values high by segregating 'better' and 'lesser' land uses...
ny law created 5 zones with differences based on land use and value, residential was granted highest (weathly wanted stable land values because of threat from working folks 'around the corner'), priority, then business (distinguished by building height, taller considered less desirable), warehouses and industries at bottom...
real estate interests in state after state lobbied for legislation granting cities authority to zone, city after city followed nyc lead, most essentially copied its law, zoning became chief weapon used by real estate interests within cities to protect land prices, and feds granted approval with standardized zoning act in 1920s... mh