The Reconstruction era in American history spanned the period immediately following the Civil War until roughly the Compromise of 1877. It aimed to rebuild the nation, reintegrate the former Confederate states, and address the social and political ramifications of slavery. During this period, the 13th, 14th, and 15th Amendments were ratified, effectively abolishing slavery and granting civil rights and suffrage to newly freed slaves. Institutions like the Freedmen's Bureau were established to aid in economic and social transformation, and Congress enacted laws to protect civil rights, particularly in the South.

However, the period was fraught with challenges and resistance. Southern Bourbon Democrats,^[72] known as "Redeemers," President Andrew Johnson, and groups like the Ku Klux Klan actively opposed the expansion of rights for Black Americans. Violence against freedmen was rampant, especially before the Enforcement Acts of 1870 and 1871, which sought to curb Klan activities. President Ulysses S. Grant initially supported robust measures to protect Black citizens, but waning political will in the North and a growing call for the withdrawal of federal troops from the South weakened Reconstruction efforts.

In spite of its limitations and failures, including the lack of reparations for former slaves and the issues of corruption and violence, Reconstruction had important accomplishments. It succeeded in reintegrating the Confederate states into the Union and laid the constitutional groundwork for civil rights, including national birthright citizenship, due process, and equal protection under the law. However, the full realization of these constitutional promises would take another century of struggle.