c) Fourteenth Amendment
The Fourteenth Amendment was ratified in 1868 and guaranteed all citizens “equal protection of the laws,” including former enslaved Black Americans.
Under the Equal Protection Clause, located at the end of Section 1 of the Fourteenth Amendment, “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.”
The Fourteenth Amendment would become the basis for many landmark Supreme Court decisions. You can read more about it here.