The Reconstruction era was a period in US history that followed the American Civil War (1861–1865) and was dominated by the legal, social, and political challenges of the abolition of slavery and reintegration of the former Confederate States into the United States. Three amendments were added to the United States Constitution to grant citizenship and equal civil rights to the newly freed slaves. To circumvent these, former Confederate states imposed poll taxes and literacy tests and sought to intimidate and control African Americans and discourage or prevent them from voting.
Throughout the war, the Union was confronted with the issue of how to administer captured areas and handle slaves escaping to Union lines. The United States Army played a vital role in establishing a free labor economy in the South, protecting freedmen's rights, and creating educational and religious institutions. Despite its reluctance to interfere with slavery, Congress passed the Confiscation Acts to seize Confederates' slaves, providing a precedent for President Abraham Lincoln to issue the Emancipation Proclamation. Congress established a Freedmen's Bureau to provide much-needed food and shelter to the newly freed slaves. As it became clear the Union would win, Congress debated the process for readmission of seceded states. Radical and moderate Republicans disagreed over the nature of secession, conditions for readmission, and desirability of social reforms. Lincoln favored the "ten percent plan" and vetoed the Wade–Davis Bill, which proposed strict conditions for readmission. Lincoln was assassinated in 1865, just as fighting was drawing to a close. He was replaced by Andrew Johnson, who vetoed Radical Republican bills, pardoned Confederate leaders, and allowed Southern states to enact draconian Black Codes that restricted the rights of freedmen. His actions outraged many Northerners and stoked fears the Southern elite would regain power. Radical Republicans swept to power in the 1866 midterm elections, gaining majorities in both houses of Congress.