Courts have been used by civil rights activists to challenge existing discriminatory laws, practices, and customs. Court cases have been filed to challenge racial segregation in areas such as education, voting, employment, housing, and public transportation. Some of these cases have been appealed to the U.S. Supreme Court, which determines whether or not laws are constitutional. In the landmark Supreme Court decision, Brown v. Board of Education of Topeka, 347 U.S. 483 (1954), a unanimous Court declared segregation in public schools unconstitutional. Brown signaled the beginning of the end of de jure segregation (or segregation that is mandated through laws) in the South, and marked the birth of the modern Civil Rights Movement. In 1955, a second Brown decision (Brown II) ordered the desegregation of public schools in the South "with all deliberate speed." Despite this ruling, most of the schools in the South remained segregated for nearly two decades after the decision as a result of the massive resistance by the states to comply with the Supreme Court's ruling.