Plessy v. Ferguson was a landmark decision of the Supreme Court of the United States concerning racial segregation. In this 1896 ruling, the court established the policy of "separate but equal" public facilities for blacks and whites. The decision formed the basis of widespread segregation in the South for over 50 years.

The case began in 1892, when Homer A. Plessy challenged a Louisiana law that required separate but equal facilities for blacks and whites in railroad cars. John H. Ferguson, a criminal district court judge, overruled Plessy's plea that the law was unconstitutional. Plessy then brought action against Ferguson. Plessy argued that the law violated a clause of the 14th Amendment to the U.S. Constitution that guaranteed citizens equal protection of the laws. The Supreme Court ruled that the amendment did not seek to guarantee the social equality of all races. The court upheld the Louisiana law. Segregation of the races in the South continued, though facilities for blacks were nearly always inferior to those for whites.