White flight
White flight generally refers to the movement of large percentages of Caucasian Americans out of racially mixed United States city centers and into largely homogenous suburban areas during the 20th century. The result of this migration, according to theorists studying shrinking cities, was the loss of money and infrastructure from urban centers. As the wealthier and more politically powerful populations fled from cities, so too did funding and government interest. The result, according to many academics, was the fundamental decline of urban health across United States cities beginning in the 20th century.