Its third article was the sole one referred to as fastening forever the institution of slavery on the inhabitants of this vast empire. There are those yet living who deny that, even under the present Constitution of the United States or the constitutions of the States since erected therein, slavery is lawfully excluded therefrom.
This article reads:
"The inhabitants of the ceded territory shall be incorporated in the Union of the United States, and admitted as soon as possible, according to the principles of the Federal Constitution, to the enjoyment of all the rights, advantages, and immunities of citizens of the United States; and in the meantime they shall be maintained and protected in the enjoyment of their liberty, property, and the religion they profess."
Justice Catron, of the United States Supreme Court, speaking in the Dred Scott case, for the majority of the court and of this article, says:
"Louisiana was a province where slavery was not only lawful, but where property in slaves was the most valuable of all personal property. The province was ceded as a unit, with an equal right pertaining to all its inhabitants, in every part thereof, to own slaves."
He and others of the concurring justices held that the inhabitants at the time of the purchase, also all immigrants after the cession, were protected in the right to hold slaves in the entire purchase.
Near the close of his opinion, still speaking of this article and the acquired territory, he says:
"The right of the United States in or over it depends on the contract of cession, which operates to incorporate as well the Territory as its inhabitants into the Union.
"My opinion is that the third article of the treaty of 1803, ceding Louisiana to the United States, stands protected by the Constitution, and cannot be repealed by Congress."
This view was heroically combatted by a minority of the court, especially by Justices McLean and Curtis. The latter, in his opinion, said