Suburbanisation
The first  moves to suburbanization were the establishment of garden cities in England, and the establishment of better off neighbourhoods in the US and Europe. Both happened in the late 19th and early 20th century. Suburbanization and urban sprawl started in the U.S. in the 1920s, when cars became affordable. In 1939, 13 percent of the peolple in the U.S. lived in suburbs; in 2010, they were over 50 percent.