Answer to Question 1
White flight is the migration of whites with European ancestry from urban regions that are racially mixed to mostly white suburbs or exurbs.
Soldiers returning from World War II were encouraged to buy houses through the GI Bill of Rights. Many soldiers had young families, were starting new careers or training, and sought somewhere with a low crime rate, good schools, and gainful employment. This, plus local codes in many suburbs restricting sale to minorities led to mostly white suburban areas and exurban areas that were middle class.
Answer to Question 2
Before 1960, the suburbs were overwhelmingly white. With fair housing laws that prohibited discrimination in housing, many local formal and informal ordinances that prohibited home sales to minorities were declared unconstitutional. This plus increasing prosperity among African Americans resulted in the rapid suburbanization of African Americans and other minorities.