The Fourteenth Amendment to the United States Constitution is one of the post-Civil War amendments and it includes the Due Process and Equal Protection Clauses. It was proposed on June 13, 1866, and ratified on July 9, 1868.
The amendment provides a broad definition of national citizenship, overturning a central holding of the Dred Scott case. It requires the states to provide equal protection under the law to all persons (not only to citizens) within their jurisdictions.
Current Supreme Court Justice David Souter has called this amendment "the most significant structural provision adopted since the original Framing". (McCreary County v. ACLU of Kentucky (2005)), although the true significance of the Amendment was not realized until the 1950s and 1960s, when it was interpreted to prohibit racial segregation in public schools and other facilities in Brown v. Board of Education.
The 14th amendment states that states must provide equal protection to all people. It also defines what citizenship is.
All persons born or naturalized in the United States, and subject to the jurisdiction thereof, are citizens of the United States and of the state wherein they reside. No state shall make or enforce any law which shall abridge the privileges or immunities of citizens of the United States; nor shall any state deprive any person of life, liberty, or property, without due process of law; nor deny to any person within its jurisdiction the equal protection of the laws.