What does the Fourteenth Amendment prohibit?

The Fourteenth Amendment prohibits states from denying any person within their jurisdiction equal protection of the laws or due process of law, and it bars states from abridging the privileges or immunities of citizens of the United States. Ratified on July 9, 1868, three years after the end of the Civil War, the amendment reshaped the relationship between state governments and the people who live within their borders.

Section 1 contains the most consequential prohibitions. The Citizenship Clause defines as U.S. citizens all persons born or naturalized in the United States, and subject to the jurisdiction thereof, overruling the Supreme Court's decision in Dred Scott v. Sandford (1857). The Privileges or Immunities Clause prohibits states from making or enforcing any law which shall abridge the privileges or immunities of citizens of the United States, although the Slaughterhouse Cases (1873) gave it a narrow reading. The Due Process Clause forbids states from depriving any person of life, liberty, or property, without due process of law. The Equal Protection Clause forbids states from denying any person within their jurisdiction the equal protection of the laws.

Together these prohibitions extend the Bill of Rights to state governments through the doctrine of incorporation, beginning with Gitlow v. New York (1925) for free speech and continuing through dozens of cases over the past century. Specific applications include Brown v. Board of Education (1954), which used the Equal Protection Clause to end public school segregation; Loving v. Virginia (1967), which struck down state bans on interracial marriage; Reed v. Reed (1971), which extended equal protection to sex-based classifications; United States v. Virginia (1996), which struck down male-only admissions at the Virginia Military Institute; Plyler v. Doe (1982), which barred Texas from charging undocumented children for K-12 education; Romer v. Evans (1996), which struck down a Colorado provision targeting gay rights; and Obergefell v. Hodges (2015), which required states to license and recognize same-sex marriages.

The Due Process Clause prohibits both procedural unfairness, requiring notice and an opportunity to be heard before government action, and substantive deprivations of fundamental rights such as those recognized in Griswold v. Connecticut (1965) and Lawrence v. Texas (2003). Section 5 grants Congress power to enforce the amendment by appropriate legislation, the constitutional foundation for the Civil Rights Act of 1964 and the Voting Rights Act of 1965. Naturalization candidates should know the Fourteenth Amendment as the principal restraint on state government power.