The Founding Fathers, framers of the United States Constitution, owned slaves. The original, remarkable document they constructed, which has withstood more than 200 years of conflict, war and turmoil, guaranteed specific inalienable freedoms to Americans of any stripe, except for individuals considered property. The creators of the Constitution allowed slavery through shortsightedness or through economic need; nevertheless, slavery was and is an absolute violation of Constitutional rights.

The Preamble

The first words of the Constitution, the preamble, abrogate slavery if the reader accepts slaves as human beings rather than as property. Civilized individuals probably accept as a given that enforced servitude is unjust; the preamble promises to "establish Justice." The ill-treatment of slaves in America is legendary; the preamble promises to "promote the general Welfare." Finally, the very definition of slavery incorporates lack of freedom; the preamble ends with a guarantee to "secure the Blessings of Liberty to ourselves and our Posterity." Significantly, liberty, welfare and justice are all capitalized in the preamble of the Constitution.

The Constitution Violates Itself

Ironically, certain sections of the Constitution, as originally codified by the Constitutional Convention of 1787, violate themselves. Despite the document's spirit of justice and liberty for all, specific clauses exist as compromises to slave-owning states, which had sent enormous delegations to the convention. One such clause is the Enumeration Clause, Article 1, Section 2, Clause 3. Designed to apportion representation based on a state's population, it includes the phrase "other persons" designated as three-fifths of a human being. Southern states thus padded their representative block with their additional slave population.

The 13th Amendment Makes It Official

The central amendment that designates slavery as a violation of the Constitution is the 13th Amendment, famously proposed by Abraham Lincoln, passed by the U.S. Congress by a bare two-thirds minimum vote, and adopted on December 18, 1865. The anti-slavery issue, originally argued furiously at the 1787 Convention, took seven decades of Constitutional legislation to come to fruition. The amendment notes, "Neither slavery nor involuntary servitude ... shall exist within the United States." This single sentence stands as the boldest official statement declaring the unconstitutional nature of slavery.

The Reconstruction Amendments

The amendments that followed the 13th -- the 14th and 15th -- further guaranteed Constitutional liberties to previously indentured individuals. The 14th granted citizenship to individuals "born or naturalized" in the United States, while the 15th prohibited the disenfranchisement of citizens regardless of “race, color, or previous condition of servitude." Known as the Reconstruction amendments, they also granted Congress the right of enforcement, which ultimately led to the Civil Rights movement of the 1960s.