“There are three basic reasons why America’s older cities are now ringed by incorporated suburbs that emphasize their distinctiveness from rather than their relationship with the metropolis: (1) sharper racial, ethnic, and class distinctions, (2) new laws that made incorporation easy and annexation unworkable, and (3) improved suburban services.” (150)

(Jackson, Kenneth T. Crabgrass Frontier: The Suburbanization of the United States. New York: Oxford University Press, 1985. Print.)