The emerging planning and public health professions saw crowded urban communities as unsafe and unhealthy places. Neighborhoods with tall tenements and narrow crowded streets lacked trees and green spaces and didn’t allow fresh air and sunlight into homes. Disease was easily transmitted between individuals. Residents were exposed to noxious fumes, noise, chemicals and waste from nearby industries.

Planners sought to change these unpleasant realities. The United States adapted the European practice of zoning to regulate land uses for protecting community health, safety and welfare. Incompatible land uses, such as homes, stables, workshops and factories, were separated. Residents moved from dense urban tenements into single-family, detached homes in the suburbs. Zoning decentralized the city with the goal of improved health and quality of life.²

A 1926 U.S. Supreme Court case recognized the constitutional authority of municipalities to use zoning to separate land uses.³  While this decision was based on the health and safety benefits for residents, one consequence was the creation of homogeneous neighborhoods where people with similar incomes and backgrounds had the means to settle. Employment centers, shopping facilities and homes grew father apart. This era of zoning practice, accompanied in many cases by deed restrictions barring some homebuyers based on race, religion or ethnicity, resulted in the economic and racial segregation of neighborhoods that persists in many areas, further exacerbating the health disparities many communities experience today.⁴