This is true. The zoning laws that led to suburbia were introduced in the 1910s and 1920s by well-meaning "progressives" who decried the ability of the rich to cloister themselves in country estates while the poor were forced to live among commerce in the city.

They won, and the result was the legislation of vast suburban "residential" zones where commercial business was prohibited, with minimum lot sizes and setbacks and minimum space between houses.