The primary purpose of Reconstruction was to ensure that the defeated South would not rise again. To this end, the system of government in the defeated states was reorganized to keep out those who'd played a part in the Confederacy and to give voting rights and opportunities for participation in public life to the newly-freed slaves.

All of the former Confederate states were now under the control of the US army. They were there to keep order and to ensure that the policy of Reconstruction was enacted properly. Under the auspices of the army, new state governments were formed in the former Confederacy, with Republicans taking over the reigns of power, which had traditionally been in the hands of Southern Democrats. In a huge leap forward for civil rights, the newly-freed slaves were allowed to vote for the new state legislatures. Not only that, but they were allowed to stand for public office.

At the same time, white Southerners who had held important positions under the Confederacy were denied the vote and barred from public office. That said, former Confederates were generally treated quite leniently by the Union authorities. This was because the Reconstruction policy under President Andrew Johnson was one of reconciliation rather than punishment.