American civil rights movement, a mass protest movement against racial segregation and discrimination in the southern United States that came to national prominence during the mid-1950s. This movement had its roots in the centuries-long efforts of African slaves and their descendants to resist racial oppression and abolish the institution of slavery. Although American slaves were emancipated as a result of the Civil War and were then granted basic civil rights through the passage of the Fourteenth and Fifteenth amendments to the U.S. Constitution, struggles to secure federal protection of these rights continued during the next century. Through nonviolent protest, the civil rights movement of the 1950s and ’60s broke the pattern of public facilities’ being segregated by “race” in the South and achieved the most important breakthrough in equal-rights legislation for African Americans since the Reconstruction period (1865–77). Although the passage in 1964 and 1965 of major civil rights legislation was victorious for the movement, by then militant black activists had begun to see their struggle as a freedom or liberation movement not just seeking civil rights reforms but instead confronting the enduring economic, political, and cultural consequences of past racial oppression.