American attitudes about African civil rights did not change significantly by 1870. While the Civil War and the passage of the 13th, 14th, and 15th Amendments abolished slavery and granted African Americans legal rights, racial prejudice and discrimination remained deeply ingrained in American society. In the post-war era, many Southern states enacted Black Codes, which severely restricted the rights of African Americans, while Northern states often practiced de facto segregation and discrimination in housing, employment, and education. The Ku Klux Klan, established in 1865, emerged as a leading perpetrator of racial violence and terrorist acts aimed at preventing African Americans from exercising their newly gained rights. Despite these obstacles, African Americans continued to advocate for their civil rights through organizations like the National Association for the Advancement of Colored People (NAACP), which was founded in 1909. It would take many more decades of struggle and social change before substantial advancements in civil rights were achieved in the mid-20th century.