The Fourteenth Amendment, one of the three Reconstruction Amendments, enshrined in the U.S. Constitution the principle that had formed the basis for the Civil Rights Act of 1866: that all people born in the United States were U.S. citizens in addition to being citizens of the states in which they resided. The amendment prohibited the states from abridging the privileges and immunities attendant to U.S. citizenship; denying anyone life, liberty, or property without due process of law; and denying anyone the equal protection of the law. As a result, the federal courts were opened to a large number of suits claiming that state legislation had violated the provisions of the Fourteenth Amendment, and such suits eventually became a significant tool of the African American civil rights movement of the twentieth century.