Jim Crow laws were state and local laws that enforced racial segregation in the Southern United States. Enacted by white Democratic-dominated state legislatures in the late 19th century after the Reconstruction period, these laws continued to be enforced until 1965. They mandated de jure racial segregation in all public facilities in the states of the former Confederate States of America, starting in 1896 with a separate but equal status for African Americans in railroad cars. Public education had essentially been segregated since its establishment in most of the South after the Civil War. This principle was extended to public facilities and transportation, including segregated cars on interstate trains and, later, buses. Facilities for African Americans were consistently inferior and underfunded compared to those which were then available to European Americans; sometimes they did not exist at all. This body of law institutionalized a number of economic, educational, and social disadvantages. De jure segregation existed mainly in the Southern states, while Northern segregation was generally de facto—patterns of housing segregation enforced by private covenants, bank lending practices, and job discrimination, including discriminatory labor union practices. Jim Crow was a pejorative expression meaning Negro.

Jim Crow laws—sometimes, as in Florida, part of state constitutions—mandated the segregation of public schools, public places, and public transportation, and the segregation of restrooms, restaurants, and drinking fountains for whites and blacks. The U.S. military was already segregated. President Woodrow Wilson, a Southerner, initiated segregation of federal workplaces at the request of southern Cabinet members in 1913.

These Jim Crow laws revived principles of the 1865 and 1866 Black Codes, which had previously restricted the civil rights and civil liberties of African Americans. Segregation of public (state-sponsored) schools was declared unconstitutional by the Supreme Court of the United States in