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With the United States starkly divided and with many Americans asking what kind of nation we are, it seems a good moment to look back to November 1863 in Gettysburg, Pennsylvania, when Abraham Lincoln tried to answer the same question. Consecrating a Civil War battlefield where thousands of young men and boys had died four months before, he spoke of a nation “conceived in liberty, and dedicated to the proposition that all men are created equal.” For most Americans since, and for much of the world, those words have at­tained the status of scripture. We draw our sense of collective identity from them. They were, however, not strictly true, and Lincoln knew it.

This essay is adapted from The War Before the War: Fugitive Slaves and the Struggle for America’s Soul From the Revolution to the Civil War, by Andrew Delbanco.

Five years earlier, he had been more candid. Speaking in Chicago in the summer of 1858, Lincoln noted that when the republic was founded, “we had slavery among us,” and that “we could not get our Constitution unless we permitted” slavery to persist in those parts of the nation where it was already entrenched. “We could not secure the good we did secure,” he said, “if we grasped for more.” The United States, in other words, could not have been created if the eradication of human bondage had been a condition of its creation. Had Lincoln said at Gettysburg that the nation was con­ceived not in liberty but in compromise, the phrase would have been less memorable but more accurate.

The hard truth is that the United States was founded in an act of accommodation between two fundamentally different societies. As one Southern-born antislavery activist wrote, it was a “sad satire to call [the] States ‘United,’” because in one-half of the country slavery was basic to its way of life, while in the other it was fading or already gone. The Founding Fathers tried to stitch these two nations together with no idea how long the stitching would hold.

There were many reasons why this composite nation unraveled in the mid-19th century—but one in particular exposed the idea of the “United” States as a lie. This was the fact that even before the founding, enslaved people repeatedly risked their lives to flee their mas­ters in search of freedom. The Founding Fathers knew the problem firsthand. Many of them were slaveholders themselves, including Thomas Jefferson and George Washington, whose own slaves periodically ran away. And so, in Article IV, Section 2, Clause 3 of the Constitution, which came to be known as the Fugitive Slave Clause, they tried to solve the problem. That clause declared that “no person held to service or labor in one state” could escape from coerced labor by fleeing from a state where slavery was legal to a state where it was illegal.

The constitutional principle was clear, but it proved to be unenforceable. Over the first half of the 19th century, as enslaved men and women ran from slavery to freedom, the federal government remained too weak to do much to stop them. By the second quarter of the century, some of the fugitives—the most famous was Frederick Douglass—were telling their stories with the help of white abolitionist editors in speeches and memoirs that ripped open the screen behind which America tried to conceal the reality that a nation putatively based on the principle of human equal­ity was actually a prison house in which millions of Americans had virtu­ally no rights at all. By awakening Northerners to this fact, and by enraging Southerners who demanded the return of their “absconded” property, they pushed the nation toward confronting the truth that America was really two nations, not one.

Politicians of all parties pretended otherwise. From the mid-1830s to the mid-1840s, hoping to restore “tranquility to the public mind,” the House of Representatives observed what became known as the Gag Rule, which required that any petition demanding action against slavery must be tabled immediately upon receipt without debate. Yet the truth about the divided state of the union could not be squelched. As the nation expanded westward, the border between slave states and free states became longer and more porous, and slaves continued to cross it.

In 1846, with the outbreak of the Mexican War, the final reckoning was set in motion. With strong but not universal support in the South, and against strong but not universal resistance in the North, both halves of the United States joined to wage a war of conquest. By the time the fighting ended two years later, the United States had seized a huge swath of land stretching from Texas to California, nearly equal in size to one-third of our present-day nation. This immense expansion of territory under con­trol of the federal government brought back the old question of compro­mise between slavery and freedom in a new form and with more urgency than ever. Would slavery be confined to states where it already existed, or would it be allowed to spread into the new territories, which would eventually become states? A growing number of white Northerners in­sisted on the former. White Southerners almost universally demanded the latter. The fragile political truce that had held the United States together was coming apart.

In 1850, Congress attempted a last-ditch solution. It struck a bargain, now known as the Compromise of 1850, that belongs to the long history of compromise—beginning with the Constitution itself—by which white Americans advanced their interests at the expense of black Ameri­cans. In an intricate balancing act designed to prevent an irreparable rup­ture between the free states and the slave states, the compromise proposed to keep slavery out of some of the new territories while leaving its future in others to be decided by local referendum.

Congress sealed the deal by passing what became known as the Fugitive Slave Act, which was an effort to put teeth into the toothless clause of the Constitution. The new law empowered a whole class of federal officers (called “commissioners”) to return fugitives without any semblance of due process. It made it a federal crime for any citizen to aid a fugitive in flight from “service.” Meant to be a remedy and salve, it turned out to be the incendiary event that lit the fuse that led to civil war.

The leading intellectual of the North, Ralph Waldo Emerson, called the Fugitive Slave Law a “sheet of lightning at midnight.” To him and many others, it revealed that Americans had been living all along in an unholy “union between two countries, one civilized & Christian & the other barbarous.”

This was a sentiment with which Lincoln himself tacitly agreed. But he refrained from saying so on the grounds that, with time, slavery could be “put in the path of ultimate extinction.” Faced with a choice between denying the constitutional right of slave owners to recover their human property and thereby losing the union, and tolerating slavery to the extent of returning fugitives and thereby saving the union, Lincoln chose the latter. “I hate to see the poor creatures hunted down and returned to their stripes,” he said, “but I bite my lip and keep quiet.”

The quiet did not last. Vile as it was, the Fugitive Slave Law was also, ironically, a gift to antislavery activists because wherever it was enforced, it allowed them to show off human beings dragged back to the hell whence they came—a more potent aid to the cause than any speech or pamphlet. It implicated Northerners in the business of slavery in a way they had never felt before. It made visible the suffering of human beings who had been hitherto invisible. It forced Northerners to choose between coming to their aid in defiance of the law or surrendering them under penalty of the law.

A few chose the former and most chose the latter, as resistance broke out in Northern cities. Blacks and whites organized to break fugitives out of jail. Most important for the fate of the union, mainstream public opinion underwent a radical change. In Massachusetts in 1854, after a fugitive was violently arrested and sent back to his master in Virginia, one New England industrialist whose textile mills wove slave-grown cotton into cloth remarked, “We went to bed one night old-fashioned, conservative, Compromise Union Whigs & waked up stark mad Abolitionists.” In North Carolina, one newspaper announced, “Respect and Enforce the Fugitive Slave Law as it stands. If not, we leave you!”

The Fugitive Slave Law turned the nation upside down. Southerners who had once insisted on states’ rights now demanded federal intervention to enforce what they considered their property rights. Northerners who had once derided the South for its theory of “nullification”—John C. Calhoun’s idea that acts of Congress require consent from each individual state before they can take effect within its borders—now became nullifiers themselves. The Fugitive Slave Law clarified just how incompatible North and South had become. It broke the national Democratic Party into Northern and Southern factions. It fractured the Whig Party into “Cotton Whigs” and “Conscience Whigs.” It made the possibility of disunion, once an extremist idea, seem suddenly plausible. One eminent New Englander replied to the Southern secessionist threat with a shrug of disgust: “If the union be in any way dependent on an act so revolting in every regard, then it ought not to exist.”

Most important, the Fugitive Slave Law of 1850 made clear that slavery was not a Southern phenomenon but a national phenomenon. Northerners who had once been able to pretend that slavery had nothing to do with them could no longer evade their complicity.

Considering this history may help put into perspective our contemporary anxiety that America is a hopelessly divided nation facing insoluble problems. In fact, none of the issues of our time—economic inequality, affordability of health care, future of the environment, regulation of immigration—recalcitrant as they may be to bipartisan compromise, compares even remotely to the impasse of the mid-19th century. “Humanity cries out against this vast enormity,” Herman Melville wrote a year before the Fugitive Slave Law was passed, “but not one man knows a prudent remedy.” By “prudent” he meant some way of destroying slavery without destroying the union itself.

Yet the story of the Fugitive Slave Law is also a distant mirror in which we may see a version of ourselves. It alienated many Americans from their country and compelled them to decide how to behave in the face of federal laws and actions that violated their personal convictions. Many white people in the North struggled to find a way, as one antislavery minister put it, “to obey the law while respecting themselves.” Writing with a certain voyeuristic pleasure, Nathaniel Hawthorne described one New England politician oscillating between saying yes and saying no to the Fugitive Slave Law, attempting “first to throw himself upon one side of the gulf, then on the other,” until he “finally tumbled headlong into the bottomless depth between.” In Boston, a U.S. marshal reluctantly obeyed a court order to send a fugitive back to slavery, then raised money to try to buy the same man’s freedom and after the Civil War hired him to work as an employee of the federal government.

Through most of his career, Lincoln himself tried to walk the line between compliance and resistance to the Fugitive Slave Law. Repulsed by the Southern demand that “we must arrest and return their fugitive slaves with greedy pleasure,” he nevertheless pledged to respect the law. Even after his election as president and well into the Civil War, he continued trying to reconcile his revulsion at slavery with his devotion to the union. Accused from the right of being an antislavery radical, he was reviled from the left for dragging his feet in the struggle against slavery for the sake of the illusory dream that the union could be preserved.

In that sense, Lincoln was the embodiment of America’s long struggle to remake itself as a morally coherent nation. Under his leadership, the Civil War finally resolved the problem of fugitive slaves by destroying the institution from which they had fled. By the time of his death, some 4 million black Americans were no longer at risk of forcible return to their erstwhile masters. They had entered the limbo between the privations of their past and the future promise of American life—a state of suspension in which millions of black Americans still live.

The problem of the 1850s was a political problem specific to a particular time and place. But the moral problem of how to reconcile irreconcilable values is a timeless one that, sooner or later, confronts us all.

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