As John McCormack notes, Tom Cotton may have been awkward in his phrasing, but there is nothing shocking in saying of slavery, “As the Founding Fathers said, it was the necessary evil upon which the union was built, but the union was built in a way, as Lincoln said, to put slavery on the course to its ultimate extinction.” Jonathan Chait writes:
Cotton seems not to be saying that slavery was necessary in order to get slave owners to accept the union, but that it was necessary to the “development of our country.” Here, oddly enough, he is recapitulating one of the most important errors in the 1619 Project itself.
There are two ways to read “necessary”: that slavery was necessary to build the country, or that tolerating the pre-existing institution was necessary because nationwide abolition was politically and perhaps economically and socially infeasible in 1776 or 1787. I agree with Chait that the 1619 Project is off-base in claiming the former; I do not read Cotton as saying that, and the people who are jumping on him over this are, it appears, just people who already hate Tom Cotton.
The formulation that slavery was tolerated as a necessary evil at the time of the Founding, and that the Founders expected (overoptimistically) that it was on an inevitable path to extinction, is a fairly standard one, and mostly an accurate way of putting the more complicated story of Founding-era slavery and anti-slavery into a nutshell. It most accurately captures the views of the Virginia Founders (such as Washington, Jefferson, Madison, and George Mason), who saw slavery as wrong — unlike John C. Calhoun and his followers in a later generation, who framed it as a positive good — but were unwilling or unable to face the effort to end it. It also accurately captures the view of anti-slavery delegates to the Constitutional Convention, who concluded that it was not worth breaking up the new nation in a vain effort to force the South to abandon slavery immediately.
Was the Constitution designed to “put slavery on the course to its ultimate extinction”? Here is where things get much more historically contested, but there is much to be said for Lincoln’s view. While it was the expressed hope of some of its Framers that the institution would be set on that path, the Constitution did not arm the federal government to do so. The new federal government was empowered only to ban the slave trade (as it did in 1807), ban slavery in new, federally administered territory (as it did immediately in 1787, and again to an extent in 1820 and 1850), and ban slavery in the District of Columbia (as it never did before the Civil War). Abolition would, under the Constitution, have to come state by state.
That process seemed underway in 1787: While slavery was legal in every colony before the Revolution, five of the thirteen states had banned slavery under the Articles of Confederation between 1780 and 1784, as did Vermont (then an independent republic) in its 1777 constitution. Even Virginia, after passing a voluntary-manumission law in 1782, had a serious legislative debate in 1785 over abolition. The one directly pro-slavery provision of the new Constitution, which was not in the Articles of Confederation — the fugitive slave clause — was added only because, when the Articles were drafted in 1776, there were no free states for slaves to escape to.
As Sean Wilentz details in his deeply researched book No Property In Man, the Framers were very careful to preserve the space for states to abolish slavery, and to refer to slaves at all points in the document as people, not property. One example illustrates how the Constitution protected anti-slavery. The Founders were deeply concerned with the sanctity of private property and private contracts. A significant impetus for the Constitutional Convention was debtors’ revolts and resulting state laws repudiating contracts.
One of the significant restrictions the Constitution placed on states was the first clause of Article I, Section 10: “No State shall . . . pass any Bill of Attainder, ex post facto Law, or Law impairing the Obligation of Contracts.” Among other things, the Contracts Clause stood as an obstacle to states immediately freeing indentured servants, who had entered into a relationship of servitude of their own free will (however exploitative) for a period of years. They could agree, in order to repay debts, to extend their term of service. States could ban new contracts of this nature, but they could not free people from previously entered contracts.
Slaves were different: They had not consented to be slaves, they were legally treated as property in the same way a horse or a dog was property, and they were bound for life, not for a fixed term. The Fifth Amendment, added in 1791, protected property rights against the federal government, which could not take a man’s property without just compensation or without due process of law. But unlike contracts, states were not in any way restricted from taking property — not until the Fourteenth Amendment, passed after the national abolition of slavery. What that meant, in practice, was that a state could destroy property rights in slaves — by recognizing the slaves as free citizens — without offending the Constitution.
That mattered a great deal in New York and New Jersey, the two Northern states that still had significant slave populations in 1787. The abolition of slavery in those two states took place in 1799 and 1804. In both states, there was fierce resistance by slaveholders, who argued that their property rights were being violated. Had the federal Constitution protected property in the way that it protected contracts, abolition in New York and New Jersey would have been impossible.
As it turned out, unfortunately, those were the last dominoes to fall. New free states would be admitted, but no existing state would abolish slavery again until the Civil War — not even Delaware, where free black citizens outnumbered slaves ten to one by 1860. The Founders’ optimism was misplaced. But they did have a plan; it just didn’t work out the way they expected.