How and why did reconstruction policies change over time?

Answer: Reconstruction (1865-1877), the turbulent era following the Civil War, was the effort to reintegrate Southern states from the Confederacy and 4 million newly-freed slaves into the United States. Under the administration of President Andrew Johnson in 1865 and 1866, new southern state legislatures passed restrictive "black codes" to control the labor and behavior of former slaves and other African Americans.