In the 1960s a number of U.S. Supreme Court cases starkly posed the conflict between the property owner's right to exclude and civil rights, in the context of "sit-ins" in restaurants that were excluding customers on racial grounds. These cases suggested, if they did not quite hold, that in this context the possessory right of the restaurant owner would have to yield to the civil-rights claim of those sitting in. In the same period a number of courts held that owners of farms could not exclude visitors from agricultural migrant labour camps.

The conflict in these cases between property rights and civil rights was made starker by the practice in the United States of treating social issues as constitutional controversies. The issue, however, of the use of property to discriminate against members of the society whom the property owner disfavours is present throughout the Western world. Ultimately in the United States the problem of restaurant sit-ins was resolved by national legislation that made it the duty of anyone providing food or lodging to serve all comers without regard to race. Similar legislation exists in many Western countries, as does legislation allowing access to premises in which workers are employed.

Black code

in the United States, any of numerous laws enacted in the states of the former Confederacy after the American Civil War, in 1865 and 1866; the laws were designed to replace the social controls of slavery that had been removed by the Emancipation Proclamation and the Thirteenth Amendment to the Constitution, and were thus intended to assure continuance of white supremacy.

The black codes had their roots in the slave codes that had formerly been in effect. The general philosophy supporting the institution of chattel slavery in America was based on the concept that slaves were property, not persons, and that the law must protect not only the property but also the property owner from the danger of violence. Slave rebellions were not unknown, and the possibility of uprisings was a constant source of anxiety in colonies and then states with large slave populations. (In Virginia during 1780-1864, 1,418 slaves were convicted of crimes; 91 of these convictions were for insurrection and 346 for murder.) Slaves also ran away. In the British possessions in the New World, the settlers were free to promulgate any regulations they saw fit to govern their labour supply. As early as the 17th century, a set of rules was in effect in Virginia and elsewhere; but the codes were constantly being altered to adapt to new needs, and they varied from one colony, and later one state, to another.

All the slave codes, however, had certain provisions in common. In all of them the colour line was firmly drawn, and any amount of Negro blood established the race of a person, whether slave or free, as Negro. The status of the offspring followed that of the mother, so that the child of a free father and a slave mother was a slave. Slaves had few legal rights: in court their testimony was inadmissible in any litigation involving whites; they could make no contract, nor could they own property; even if attacked, they could not strike a white person. There were numerous restrictions to enforce social control: slaves could not be away from their owner's premises without permission; they could not assemble unless a white person was present; they could not own firearms; they could not be taught to read or write, or transmit or possess "inflammatory" literature; they were not permitted to marry.

Obedience to the slave codes was exacted in a variety of ways. Such punishments as whipping, branding, and imprisonment were commonly used, but death (which meant destruction of property) was rarely called for except in such extreme cases as the rape or murder of a white person. White patrols kept the slaves under surveillance, especially at night. Slave codes were not always strictly enforced, but whenever any signs of unrest were detected the appropriate machinery of