“I tremble for my country when I reflect that God is just,” Thomas Jefferson wrote in 1781. The American revolution still raged, many of his own slaves had escaped, his beloved Virginia teetered on social and political chaos. Jefferson, who had crafted the Declaration of Independence for this fledgling nation at war with the world’s strongest empire, felt deeply worried about whether his new country could survive with slavery, much less the war against Britain. Slavery was a system, said Jefferson, “daily exercised in tyranny,” with slaveholders practicing “unremitting despotism”, and the slaves a “degrading submission”.

The founder was hopeless and hopeful. He admitted that slaveholding rendered his own class depraved “despots” and destroyed the “amor patriae” of their bondsmen. But his fear was universal. “Can the liberties of a nation be thought secure when we have removed their only firm basis, a conviction in the minds of the people that these liberties are of the gift of God?” This advocate of the natural rights tradition, and confounding contradictory genius, ended his rumination with the vague entreaty that his countrymen “be contented to hope” that a “mollifying” of the conditions of slaves and a new “spirit” from the revolution would in the “order of events” save his country.

Danger cannot come from abroad … If destruction be our lot, we must ourselves be its author and finisher Abraham Lincoln in 1838

For that republic to survive it took far more than hope and a faith in progress. Indeed, it did not survive; in roughly four score years it tore itself asunder over the issue of racial slavery, as well as over fateful contradictions in its constitution. The American disunion of 1861-65, the emancipation of 4 million slaves, and the reimagining of the second republic that resulted form the pivot of American history. The civil war sits like the giant sleeping dragon of American history ever ready to rise up when we do not expect it and strike us with unbearable fire. It has happened here – existential civil war, fought with unspeakable death and suffering for fundamentally different visions of the future.

Republics are ever unsteady and at risk, as our first and second founders well understood. Americans love to believe their history is blessed and exceptional, the story of a people with creeds born of the Enlightenment that will govern the worst of human nature and inspire our “better angels” to hold us together. Sometimes they do. But this most diverse nation in the world is still an experiment, and we are once again in a political condition that has made us ask if we are on the verge of some kind of new civil conflict.

In one of his earliest speeches, the Young Men’s Lyceum address, in 1838, Abraham Lincoln worried about politicians’ unbridled ambition, about mob violence, and about the “perpetuation of our political institutions”. The abolitionist Elijah Lovejoy had just been murdered by a mob the previous year in Illinois. Lincoln saw an “ill omen” across the land due to the slavery question. He felt a deep sense of responsibility inherited from the “fathers” of the revolution. How to preserve and renew “the edifice of liberty and equal rights”, he declared, provided the challenge of his generation. “At what point shall we expect the approach of danger?” Lincoln asked. “By what means shall we fortify against it?” His worries made him turn inward. “Shall we expect some transatlantic military giant to step the ocean, and crush us at a blow? Never! All the armies of Europe, Asia and Africa combined … could not by force, take a drink from the Ohio, or make a track on the Blue Ridge, in a trial of a thousand years.” Lincoln did not fear foreign enemies. If “danger” would “ever reach us”, he said, “it must spring up amongst us. It cannot come from abroad. If destruction be our lot, we must ourselves be its author and finisher. As a nation of free men, we must live through all time, or die by suicide.”

Those words were prescient in Lincoln’s own century. But they have a frightful clarity even today. Where are we now? Are Americans on the verge of some kind of social disintegration, political breakup, or collective nervous breakdown, as the writer Paul Starobin has recently asked? Starobin has written a new book, Madness Rules the Hour: Charleston, 1860, and the Mania for War, in which he revisits the old thesis that the secession moment represented a “crisis of fear” that led tragically to disunion and war. Psychologically and verbally, in the comment sections on the internet, and in talkshow television, we are a society, as Starobin shows, already engaged in a war of words. And it has been thus for a long time. Americans are expressing their hatreds, their deepest prejudices, and their fierce ideologies. It remains to be seen whether we have a deep enough well of tolerance and faith in free speech to endure this “catharsis” we seem to seek.

Facebook Twitter Pinterest Far-right protesters clash with anti-fascist demonstrators in Charlottesville. Photograph: Michael N/Pacific/BarcroftImages

Psychological explanations, however, do not fully explain America’s current political condition. We are in conflict about real and divergent ideas. Are we engaged, half-wittingly, in a slow suicide as a democracy? Are we engaged in a “cold civil war” as one writer has suggested? Or does it feel like 1859, as another expert wondered, with so much rhetorical and real violence in the air? The election, and performance in office of Donald Trump, have many serious people using words like “unprecedented”, or phrases like “where in time are we” or “we haven’t been here before”. Commentators and ordinary citizens have been asking how or where in the past we can find parallels for our current condition.

For historians, Trump has been the gift that keeps on giving. His ignorance of American history, his flouting of political and constitutional traditions, his embrace of racist ideas and groups, his egregious uses of fear, his own party’s moral bankruptcy in its inability to confront him, have forced the media to endlessly ask historians for help. That moral cowardice by Republicans shows some glimmers of hope; Mitt Romney has just called out Trump, accusing him of “unraveling … our national fabric” by his coziness with white supremacists, and Senator Bob Corker of Tennessee charged Trump with putting the nation “in great peril” by his incompetence and racism.

Sixteen years ago, in the book, Race and Reunion: The Civil War in American Memory, I made a simple claim: “As long as America has a politics of race, it will have a politics of civil war memory.” Unfortunately, despite many more fine books, as well as conferences and courses taught on the same subject, that prescription seems truer now than ever. The line from the killings of Travon Martin and Michael Brown, through a myriad of other police shootings, and then especially from the mass murder of nine African Americans in Charleston in June, 2015, to the recent white supremacist demonstration and violence in Charlottesville mark a dizzying, crooked, but clear historical process. America is in the midst of yet another of its racial reckonings which always confront us with a shock of events we are, pitifully, never collectively prepared for. Just now we are engaged in a frenzied wave of Confederate monument removals; it is a manifestation of how well-meaning Americans can demonstrate their anti-racism and full of admirable impulses. But this too in all likelihood will not itself prepare us for the next shock of events nor our next reckoning. Hence, we so achingly need to know more history.

All parallels are unsteady or untrustworthy. But the present is always embedded in the past. The 1850s, the fateful decade that led to the civil war, has many instructive lessons for us. Definitions of American nationalism, of just who was a true American, were in constant debate. After the Great Hunger in Ireland the US experienced an unprecedented immigration wave between 1845 and the mid-1850s, prompting a rapid and powerful rise of nativism. Irish and German Catholics were unwelcome and worse. The Mexican-American war of 1846-48, the nation’s first expansionist foreign conflict, stimulated an explosive political struggle over the expansion of slavery. The Fugitive Slave Act of 1850 caused a wave of “refugee” former slaves escaping the northern states into Canada, as well as a widespread crisis over violent rescues of fugitive slaves. Indeed, the constant flight of slaves from the South to free states was, in effect, America’s first great refugee crisis. The abolition movement, the country’s prototypical reform crusade, became increasingly politicized as it became more radical, extra-legal, and violent.

At every turn in that decade, Americans had to ask whether their institutions would last. The two major political parties, the Whigs and Democrats, either disintegrated or broke into sectional parts, north and south, over slavery. Third parties suddenly emerged with success like no other time in our history. First the Know-Nothings, or American party, whose xenophobia and anti-Catholicism got them elected in droves in New England in the early 1850s. And the most successful third party in our history, the Republicans, were born in direct resistance to the Kansas-Nebraska Act of 1854, championed by Democrats, and which opened up the western territories to the perpetual expansion of slavery. A succession of weak and pro-slavery presidents from 1844 through 1860 either tarnished the institution of the presidency or deepened the sectional and partisan divide.

In 1857, the supreme court weighed in by declaring in Dred Scott v Sandford that blacks were not and could never be citizens of the US. They had, wrote chief justice Roger B Taney, “for more than a century been regarded as beings of an inferior order … so far inferior that they had no rights which the white man was bound to respect.” This most notorious court decision legally opened up all of the west, and for that matter, all of the north to the presence of slavery. So discredited was the supreme court among many northerners in the wake of the decision that the Republicans made resistance to the judiciary a rallying cry of their political insurgency. That impulse led to the election of Lincoln in 1860, interpreted by most southern slaveholders, who firmly controlled that region’s politics, as the primary impulse to secede from the union. They believed they could not co-exist in a nation now led by a political organization devoted to their destruction.

By the time of the sectionalized and polarized election of 1860, conducted in a climate of violence and danger caused by John Brown’s raid on Harper’s Ferry in 1859, north and south had developed broad-based mutual conspiracy theories of each other. They did so through a thriving and highly partisan press, in both daily and weekly newspapers. Both sides tended to have their own sets of facts and their own conceptions of both history and the constitution.

White southerners feared and loathed abolitionists, and now they faced anti-slavery politicians who could truly affect power and legislation if elected. By the 1860 election, pro-slavery interests had developed a widespread theory about a “black Republican” conspiracy in the north, determined on taking hold of all reins of government to put slavery, as Lincoln in 1858 had actually said, on a “course of ultimate extinction”. In the secession crisis, one southern leader after another pronounced against what they perceived as an abolitionist conspiracy against their livelihoods and their lives. William Harris, the secession commissioner for Mississippi, claimed in December, 1860 that Republicans “now demand equality between the white and negro races, under our constitution; equality in representation, equality in the right of suffrage … equality in the social circle, equality in the rights of matrimony.” He concluded therefore, the deep south faced a stark choice: “Sink or swim, live or die, survive or perish, the part of Mississippi is chosen, she will never submit to the principles and policy of this black Republican administration.”

That Republican party, along with radical abolitionists, advanced an equally potent idea of a “slave power” conspiracy that had grown into a staple of antislavery politics. The slave power, argued northerners, consisted of the southern slaveholding political class; they were obsessively bent on control of every level of government and every institution – presidency, courts, and Congress. The slave power especially demanded control over future expansion of the United States in order for its system to survive. The theory made greater sense with time to many people, since they could see that the slave south, though wealthy, was increasingly a minority interest in the federal government.

No one made this case about the slave power better than the black abolitionist Frederick Douglass. In May, 1853 Douglass gave the slave power clear definition. It was “a purely slavery party” in national affairs and its branches reached “far and wide in church and state”. The conspiracy’s “cardinal objects” were suppression of abolitionist speech, removal of free blacks from the United States, guarantees for slavery in the west, the “nationalization” of slavery in every state of the union, and the expansion of slavery to Mexico and South America.

By 1855, as the Kansas crisis deepened, Douglass saw the slave power as an all-encompassing national plague with “instinctive rapacity”, with a “natural craving after human flesh and blood”. It was a “murderous onslaught” upon the rights of all Americans to sustain the claims of a few. Seeking consensus with the slave power, Douglass maintained, would be “thawing a deadly viper instead of killing it”. He had faith in the “monster’s” inherent tendency to over-reach and destroy itself. “While crushing its millions,” he said, “it is also crushing itself.” It had “made such a frightful noise” with the “Fugitive Slave Act… the Nebraska bill, the recent marauding movements of the oligarchy in Kansas,” that it now performed as the abolitionists’ “most potent ally”. Douglass detected a great change in northern public opinion. Instead of regarding the abolitionists as mere fanatics “crying wolf”, the masses now perceived the evil in their midst and themselves cried “kill the wolf”.

Thus we might see one of the strongest parallels of all between the road to disunion and our current predicament. The rhetoric about the slave power and about black Republicans has a familiar ring today. Millions of Americans on the right who garner their information from selective websites, radio shows and Fox News possess all sorts conspiratorial conceptions of liberals and the alleged radical views of professors on university campuses. Many on the left also know precious little about people in rural and suburban America who voted for Trump; coastal elites do sometimes hold contemptuous views bordering on the conspiratorial about the people they “fly over”. Americans are more than politically polarized; we are bitterly divided about our expanding diversity, about the proper function of government, about the right to vote and how to protect it, over women’s reproductive rights, about climate science, over whether we even believe in a social contract between citizens and the polity. In other words, like the 1850s, we are divided over conflicting visions of our future. Let us hope that we find ways to fight out our current conflicts within politics and not between each other in our over-armed society. From my perspective, we can hope that like the slave power, the white supremacist far right will become its own worst enemy, and after all its frightful noise, kill itself.

As Americans consider the survival of their own amor patriae we might reflect on just how old our story is. We love stories of exile and return, destruction and redemption. When Moses sent the Israelites across the Jordan, he instructed them to put up memory stones to mark their journey and their story. Americans have put up more than their share of memory stones, and are just now living through a profound process of deciding which ones will remain. But as we look deeply into just what our own amor patriae means, and whether it can hold together, we might think hard about what inscriptions we want written on the memory stones of our own times. We might draw one from Douglass in 1867: “We ought to have our government so shaped that even when in the hands of a bad man we shall be safe.”