Although1the civil war in the 1960s destroyed slavery in the south, slaves who had been enslaved for two centuries became free men. However, taking advantage of the federal democratic system of the United States and the advantages of white majority and strong political and economic power, the southern States passed a series of laws of apartheid and discrimination through legal democratic procedures and continued to deprive blacks of their rights. In 1896, the Supreme Court of the United States recognized the constitutionality of the apartheid system in the South in its judgment on Plessyv. Ferguson made blacks suffer legal discrimination and persecution for a century after the Civil War. It should be mentioned that the apartheid laws passed by southern States are also aimed at other ethnic minorities. The segregation facilities in the southern States are only divided into whites and colored people. The laws of southern states not only prohibit black-and-white marriages, but also expressly prohibit Asians (Mongolians) from marrying whites, and offenders will be sentenced to more than two years' imprisonment.