Ratified between 1865 and 1870, the 13th , 14th , and 15th Amendments to the Constitution, known as the “Reconstruction Amendments,” ended slavery in the United States, ensured birthright citizenship , as well as due process and “equal protection of the laws” under the federal and state governments, and expanded voting rights by prohibiting discrimination based on “race, color, or previous condition of servitude.” The Reconstruction Amendments also granted Congress the power to enforce the amendments’ provisions through federal legislation. The 14th Amendment eliminated the three-fifths rule in Article I, Sec. 2, cl. 3, and punished any state that did not permit male citizens twenty-one years old or older to vote by reducing the state’s proportional representation. This amendment also barred those who “have engaged in insurrection or rebellion” or “given aid or comfort to the enemies” of the United States from public office, unless Congress voted to remove this prohibition. The Reconstruction Amendments were essential to reuniting the United States during Reconstruction, and confederate states were required to ratify the 13th and 14th Amendments to be readmitted to the union.
The Reconstruction Amendments provided the constitutional basis for enforcement and implementation of Reconstruction and passage of federal legislation such as the Civil Rights Acts of 1866 and 1875 and the Enforcement Acts of 1870-71 to end slavery, ensure full citizenship, civil rights, and voting rights to freed African Americans and to address growing violence and intimidation against freed African Americans in the South. However, in U.S. v. Cruikshank (1875) , the Supreme Court dismissed the use of Enforcement Acts against individuals, and, in the Civil Rights Cases (1883) , the Court declared that the Civil Rights Act of 1875 , which had barred racial discrimination in public accommodations, was unconstitutional. In Plessy v. Ferguson (1896) , the Court upheld segregation laws, establishing the “separate but equal” doctrine. The end of Reconstruction in 1877 and these Supreme Court decisions paved the way for racial violence, disenfranchisement through literacy tests, and Jim Crow segregation in the South, but it also inspired legal challenges to discrimination and segregation including Brown v. Board of Ed. (1954), a Civil Rights Movement, and a Second Reconstruction a century later with the Civil Rights Act of 1964 and Voting Rights Act of 1965 .