Answer:
During Reconstruction years, many positive changes occurred for blacks.
With the victory of the Union in the Civil War, slavery was finally abolished in the United States through the incorporation of the Thirteenth Amendment to the Constitution of the United States. In addition, two other amendments were incorporated: the Fourteenth Amendment, which granted American citizenship to African Americans; and the Fifteenth Amendment, which granted them the right to vote.
These rights were effective only until the end of the Reconstruction in 1877, that is, for 12 years. In 1877 the Democrats regained control of the American South, beginning to restrain these rights again through poll tests that limited the right to vote of blacks, and different forms of precarious work that closely resembled slavery itself.