Black schools originated under legal segregation in the southern United States after the American Civil War and Reconstruction era, in southern states public policy to keep races separated and maintain white supremacy. In the United States white opposition to African-American success resulted in only the most rudimentary schools for African Americans, as proven by Gebhart v. Belton. It often took decades after the South established public schools for systems to offer education at the high school level. Nonetheless, black teachers and students created some outstanding black high schools, including Dunbar High School in Washington, D.C.; Dudley High School in Greensboro, North Carolina, and the Paul Laurence Dunbar Junior and Senior High School in Little Rock, Arkansas.
Few African Americans in the South received any education at all until after the Civil War. Slaves had been prohibited from being educated, and there were generally no public school system for white children, either. The planter elite paid for private education for its own children. Legislatures of Republican freedmen and whites established public schools for the first time during Reconstruction.
Integrated public schools meant local white teachers in charge, and they were not trusted. The black leadership generally supported segregated all-black schools.  That way black principals and teachers would be in charge, or (in private schools) else highly supportive whites sponsored by northern churches. Public schools were segregated throughout the South during Reconstruction and afterward into the 1950s. New Orleans was a partial exception: its schools were usually integrated during Reconstruction.
After the white Democrats regained power in southern states in the 1870s, during the next two decades they imposed legal Jim Crow laws. They disfranchised most blacks and many poor whites by various voter registration and electoral requirements. Services for black schools (and any black institution) routinely received far less financial