A sundown town is a municipality or neighborhood within the United States that practices or once practiced a form of racial segregation characterized by intimidation, hostility, or violence among White people directed toward non-Whites, especially against African Americans. The term "sundown town" derives from the practice of White towns then erecting signage alerting non-Whites to vacate the area before sundown. Sundown towns might include entire sundown counties or sundown suburbs and have historically been strengthened by the local presence of the Ku Klux Klan (KKK), a White supremacist organization. Discrimination practices commonly found in sundown towns became federally illegal during the 20th century.