Which amendment requires equal protection under the law?

The Fourteenth Amendment is the correct choice because it explicitly includes the Equal Protection Clause, which mandates that individuals in similar situations be treated equally by the law. Ratified in 1868, the amendment was primarily aimed at ensuring civil rights for newly freed slaves after the Civil War. It prohibits states from denying any person "the equal protection of the laws," which has been interpreted by the courts to encompass a broad range of civil rights and discrimination issues. This clause plays a critical role in various landmark Supreme Court cases, establishing the foundation for many civil rights protections that continue to be relevant today.