Racial Segregation.

“Racial segregation, the practice of restricting people to certain circumscribed areas of residence or to separate institutions (e.g., schools, churches) and facilities (parks, playgrounds, restaurants, restrooms) on the basis of race or alleged race.” http://www.britannica.com/EBchecked/topic/488135/racial-segregation.
Racial segregation was a common thing in multicultural countries. In the southern parts of the United States legal segregation was a common thing from the late 19th century into the 1950s. African Americans in the South initiated the Civil Rights movement to break the pattern of racial segregation. That movement led to the Civil Rights Act of 1964 which set strict rules against racial discrimination and segregation.