Final answer:
During Reconstruction, the Thirteenth Amendment abolished slavery, and the Fourteenth Amendment extended citizenship and equal protection under the law, significantly altering American society and the Constitution. Despite these advances, African Americans faced ongoing discrimination and resistance to their newly granted rights.
Step-by-step explanation:
The Constitution underwent significant changes during the Reconstruction era after the Civil War, with the implementation of three major amendments that were aimed at establishing and protecting the rights and equality of former slaves. The first of these changes was the Thirteenth Amendment, ratified in 1865, which abolished slavery and involuntary servitude, except as punishment for crime. Its impact was foundational, as it legally freed all slaves and transformed American society and its economic structures, primarily in the South where the plantation system had been heavily reliant on slave labor. The second fundamental change was the Fourteenth Amendment, ratified in 1868, which granted citizenship to all persons born or naturalized in the United States, including former slaves, and provided equal protection under the laws.
These amendments significantly affected life in the U.S. For example, the Fourteenth Amendment laid the groundwork for civil rights expansion and was later used to support the desegregation efforts during the Civil Rights Movement, promote gender equality, and protect the rights of marginalized groups. However, despite these legal protections, African Americans continued to face substantial discrimination and challenges, such as Jim Crow laws, voter suppression through mechanisms like literacy tests and poll taxes, and violent backlash from groups like the Ku Klux Klan.