After the Civil War, Union troops remained in the states of the former Confederacy to enforce the post-Civil War Amendments — the 13th Amendment, which made slavery illegal in the entire United States; the 14th Amendment, which gave citizen rights to the newly freed slaves; and the 15th Amendment, which provided equal civil rights for newly freed slaves. The former Confederate states had to agree to these amendments and pledge not to be insurrectionists against the United States in order rejoin the union. Soon after the War, several former Confederate states changed their state constitutions to reflect the equality expressed in the newly passed amendments. Mississippi, the heart of the Confederacy, passed one of the most progressive state constitutions in the country, granting all citizens of the state, Black and white, civil and voting rights.
The period between 1868 and 1877 was a period when Black former slaves were elected to Congress, mayor’s offices, and the courts because of the rights granted in the federal amendments and the new progressive state constitutions. This was the period known as Reconstruction.