The most critical civil rights issue in the U.S. has concerned the status of its black minority. After the Civil War the former slaves' status as free people entitled to the rights of citizenship was established by the 13th and 14th Amendments, ratified in 1865 and 1868, respectively. The 15th Amendment, ratified in 1870, prohibited race, color, or previous condition of servitude as grounds for denying or abridging the rights of citizens to vote. In addition to these constitutional provisions, statutes were passed defining civil rights more particularly. The Supreme Court, however, held several of these unconstitutional, including an 1875 act prohibiting racial discrimination by innkeepers, common carriers, and places of amusement.
During the period of Reconstruction the Republican-dominated federal government maintained troops in the southern states. Blacks voted and held political offices, including seats in Congress. The Reconstruction era aroused the bitter opposition of most southern whites. The period came to an end in 1877, when a political compromise between the Republican party and southern leaders of the Democratic party led to the withdrawal of federal troops from the South.
In the last two decades of the 19th century, blacks were disfranchised and stripped of other rights in the South through discriminatory legislation and unlawful violence . Separate facilities for whites and blacks became a basic rule in southern society. In Plessy v. Ferguson, an 1896 case involving the segregation of railroad passengers, the Supreme Court held that "separate but equal" public facilities did not violate the Constitution.
During the first half of the 20th century racial exclusion, either overt or covert, was practiced in most areas of U.S. life. The 1954 Supreme Court decision in Brown v. Board of Education represented a turning point; reversing the 1896 "separate but equal" ruling, the Court held that compulsory segregation in public