When moving away from superficial, cartoonish, and caricatured history, the importance of context and distinctions becomes obvious. Part of the task of responsible history is to show how things are often more complicated than first assumed. The Civil War is an important historical event in which this is evident. Zooming in on just one aspect of the US before the Civil War, it is key to understand the role of the federal legal protections of slavery.
While recognizing slavery’s role in secession, and secession as a cause of the war, it is often overlooked that the federal government—not just slave states—had implemented legal protections of slavery by policy for decades. Further, without these federal protections, slavery was arguably more vulnerable in the slave states that seceded from the Union. Historian Paul Johnson—who does not view secession as a legitimate right of states—writes the following,
The most the Lincoln Republicans could do, and proposed to do, was to contain slavery. To abolish it in the 1860s required a constitutional amendment, and a three-quarters majority; as there were fifteen slave states, this was unobtainable. A blocking majority of this magnitude would still have been sufficient in the second half of the 20th century. It is worth noting that, at the time of secession, Southerners and Democrats possessed a majority in both houses of Congress, valid till 1863 at least. If protecting slavery was the aim, secession made no sense. It made the Fugitive Slave Act a dead letter and handed the territories over to the Northerners. The central paradox of the Civil War was that it provided the only circumstances in which the slaves could be freed and slavery abolished. (emphasis added)
While some of Johnson’s statements could certainly be debated, and while he is known as a conservative historian who is not comfortably in the mainstream, he is no defender of secession. He recognized, along with Alexander Stephens, that the secession of certain slave states threatened the institution of slavery because it meant abandoning the protections of the federal government. Stephens wrote in a letter (July 10, 1860), “...I consider slavery much more secure in the Union than out of it…” Why was this the case, and why did many others—including key abolitionists of the time—agree that slavery was better protected in the federal Union than out of it?
In short, it was because of federal fugitive slave laws, a federal court decision, and the potential of a constitutional amendment which would have made federal tampering with state domestic institutions, including slavery, permanently impossible.
Fugitive Slave Laws
From the Constitution’s Fugitive Slave Clause (Art. IV, §2), the federal government obligated free states to return escaped slaves. Congress implemented this through the Fugitive Slave Act of 1793, which authorized slaveholders to seize alleged fugitives in free states for summary return. In Prigg v. Pennsylvania (1842), the Supreme Court barred states from obstructing rendition but held they were not required to enforce it, prompting many Northern states to pass personal liberty laws withdrawing cooperation. The Compromise of 1850 responded with a far stricter federal law—creating commissioners, denying jury trials, penalizing those who aided fugitives, financially incentivizing judges to render a guilty verdict, and requiring citizens to assist in captures. This effectively socialized the enforcement costs of slavery, shifting them from slave states to free states. In fact, many of the abolitionists—the most radical anti-slavery people of their time—actually argued that the free states ought to secede from the Union in order to void the fugitive slave laws.
For example, the radical abolitionist leader, William Lloyd Garrison, argued (December 2, 1859),
I tell you our work is the dissolution of this slavery-cursed Union, if we would have a fragment of our liberties left to us!...
By the dissolution of the Union we shall give the finishing blow to the slave system;...
Again, the abolitionists of American Anti-Slavery Society, at its regular anniversary in 1844, put forward a resolution that read, “Resolved, That the Abolitionists of this country should make it one of the primary objects of this agitation to dissolve the American Union.” Wendell Phillips—another American abolitionist—explained the abolitionist strategy in advocating for secession even if he did not entirely agree that that method should be pursued,
Disunion is a course, by which a man or a state may immediately disconnect themselves from the sin of sustaining slavery. The distant hope of Constitutional amendment not only allows, but makes it necessary, that we should remain in the Union, performing its sinful requirements while they continue the law of the land, in order to effect our object.
Historian Jeffrey Rogers Hummel—author of Emancipating Slaves, Enslaving Free Men—has written on the profitability of slavery and deadweight loss, as well as the economics of the fugitive slave laws. He argues that slavery was allowed to survive longer than usual because it was propped up and socialized by policies which shifted the costs from slaveholders to non-slaveholders, including those in free states through fugitive slave laws. He further argues that the abolitionists who advocated for the secession of the free states to put pressure on slavery may have argued for a policy more economically effective than they realized. He presents this case in his presentation “Why the North Should Have Seceded from the South.” In his dissertation, “Deadweight Loss and the American Civil War,” he wrote,
Southern slavery was indeed profitable but nevertheless inefficient; it operated like other obvious practices — from piracy through monopoly to government subsidies — where individual gains do not translate into social benefits. In the terminology of economics, it was a system that imposed significant “deadweight loss” on the Southern economy, despite being lucrative for slaveholders….
....A recognition of slavery’s deadweight loss has major implications for the origins of the Civil War. Slavery’s survival required extensive subsidies from government at all levels. A federal Fugitive Slave Law was among the most crucial ways that the national government socialized the system’s enforcement. (emphasis added)
The Dred Scott Case (1857)
The Supreme Court escalated the conflict in the infamous Dred Scott v. Sandford (1857). Scott had lived with his master in Illinois and the Wisconsin Territory—both free jurisdictions—and later sued for his freedom after returning to Missouri. He initially won his freedom in a Missouri trial court, but the Missouri Supreme Court reversed that decision. Scott then filed suit in federal court, and the case ultimately reached the US Supreme Court.
Chief Justice Roger Taney’s majority opinion held that persons of African descent—whether free or enslaved—could not be citizens of the United States and therefore lacked standing to sue in federal court. More dramatically, the Court ruled that Congress had no authority to prohibit slavery in the territories, declaring the Missouri Compromise unconstitutional. Because slaves were recognized as property under state law, and because the Fifth Amendment protected property from deprivation without due process, the Court reasoned that slaveholders had a constitutional right to bring slave property into federal territories.
In effect, the Court nationalized the protection of slave property, placing it under constitutional protection beyond the borders of slave states and further inflaming sectional tensions. The decision exposed the contradiction between slavery and property rights: if human beings were legally property in some states, and if property rights were constitutionally protected, then slavery could not be confined geographically without undermining constitutional guarantees. Therefore, at some level, slave property had to be honored, even in free states where slavery had been declared illegal.
The Corwin Amendment
Even presidents attempted to reassure and protect slavery within constitutional limits, including Abraham Lincoln. In his First Inaugural Address as president (March 4, 1861)—which took place in the context of the secession of several Southern states following Lincoln’s election—Lincoln promised that he was no threat to slavery, “I have no purpose, directly or indirectly, to interfere with the institution of slavery in the States where it exists. I believe I have no lawful right to do so, and I have no inclination to do so.” In fact, Lincoln was—at first—so opposed to using the federal government to extinguish slavery that he even mentioned his favorable support for the little-known Corwin Amendment. Lincoln said,
I understand a proposed amendment to the Constitution--which amendment, however, I have not seen--has passed Congress, to the effect that the Federal Government shall never interfere with the domestic institutions of the States, including that of persons held to service. To avoid misconstruction of what I have said, I depart from my purpose not to speak of particular amendments so far as to say that, holding such a provision to now be implied constitutional law, I have no objection to its being made express and irrevocable. (emphasis added)
This amendment promised that—whatever the states chose to do—the federal government would never interfere with slavery in the slave states and would be kept from doing so permanently. It was a last, desperate attempt to coax the seceding states back into the Union. It read,
No amendment shall be made to the Constitution which will authorize or give to Congress the power to abolish or interfere, within any State, with the domestic institutions thereof, including that of persons held to labor or service by the laws of said State.
The House approved the amendment by 133 to 65 votes (February 28, 1861). The Senate approved it on a vote of 24 to 12 (March 2, 1861). President Buchanan endorsed and signed the joint resolution transmitting it to the states (though presidential approval is not constitutionally required for amendments). After being elected, Lincoln announced that he believed that such protection of slavery was already implied in the Constitution, but that he had no objection to making it explicit. In fact, a few states—Ohio, Maryland, and Illinois—ratified it. It was proposed as what would have become the 13th Amendment, though it never received the necessary ratifications.
Conclusion
From these historical evidences it is obvious that, unfortunately, slavery was not just propped up by policy in the slave states, but federally. Through the Fugitive Slave Acts, the enforcement costs of slavery were nationalized and imposed upon free states. Through Dred Scott, slave property was placed under constitutional protection in the federal territories. Through the proposed Corwin Amendment, the federal government stood ready to make permanent its non-interference with slavery in the states. In short, the Union contained and protected slavery through law and policy for decades.
Why did slavery—an inefficient and costly labor system, benefitting only a few at the expense of everyone else—last in the US? One answer to this question is because it was protected by policy, including federal policy, privatizing the benefits for slaveholders and socializing the costs. In other words, slavery was removed from the realm of the free market, where competitive forces would have put pressure on the institution of slavery. On this, Mises wrote,
…the abolition of slavery and serfdom could not be affected by the free play of the market system, as political institutions had withdrawn the estates of the nobility and the plantations from the supremacy of the market.
