On July 4, the night sky over the Hudson Valley was clear and empty. No planes, no mist, no rain, allowing fireworks to explode with spectacular brilliance. Above the towns, the whoosh and bang sounded out something more than the usual burst of patriotic glee: the soundtrack of relief, the sense of Covid in retreat, if not yet defeated.

At home, after the oohs and ahs, a miniature percussion section (our three small grandsons) marched up and down the back deck to the strains of Sousa’s “Stars and Stripes Forever”, putting their all into saucepan-lid banging in time with the beat.

Absent from our family celebration — only because it’s currently in London storage — is an enormous, slightly moth-eaten 19th-century Union Jack. I’ve been known to hang it on July 4, not as a gesture of British party-pooping or to aggravate the neighbours, but because this particular neck of the woods has a fascinatingly mixed history as a theatre of the Revolutionary War.

The country around here, like all of America during the revolution, was divided into equally numbered thirds: Patriot, Loyalist and nervous neutrals. Across the river and a little way upstream, the improvised fort (actually earthworks) at Stony Point was established by the British general Clinton to control the Hudson, but was taken in a daring attack by “Mad” Anthony Wayne’s force of American commandos on July 16 1779.

Closer to home, at Tarrytown, the British spy Major John André; was caught, before he could reach Benedict Arnold at West Point. Documents André was carrying revealed the plan to deliver the fort to the British army and, to George Washington’s incredulous horror, the perfidy of one of his most trusted generals.

Flags — these days, the rags of polemical rage — also have a mixed history. In 1929, the dashing aviator Opal Kunz dropped a mass of them from her plane directly over the site of the battle of Stony Point. Those were the “Betsy Ross” flags created by the eponymous Patriot upholsterer, featuring red and white stripes but with the five-pointed stars of the 13 colonies arranged in a circle to symbolise, optimistically, perpetual union.

© National Archives | Flag made by Betsy Ross c1783-95

But the Betsy Ross was preceded by the Grand Union Flag, designed by the Philadelphia milliner Margaret Manny for the new fleet of the American navy. Manny’s flag had the obligatory stripes but, in place of stars, the top left canton featured the Union Jack.

But then history is a great mischief-maker, the enemy of simplicities, especially those of national allegiance. “The Star-Spangled Banner” was adopted as the American national anthem only in 1931. Prior to that, “America (My Country ’Tis of Thee)”, first performed on July 4 1831, served as patriotic hymn along with “Hail Columbia”.

Confusingly, its melody is that of the British national anthem. Which was, in fact, the point. The last line of the hymn of monarchist devotion is replaced by an American democratic alternative: “let freedom ring” supersedes “God save the king”.

But one artful contrafactum brought on another. In 1843, AG Duncan wrote a stinging, abolitionist version which begins:

My country ’tis of thee / Stronghold of slavery / Of thee I sing

The second verse is even more to the point:

My native country, thee, / Where all men are born free, / If white’s their skin

The jarring discrepancy between the “self-evident” truth of human equality asserted in the Declaration of Independence and the brutal reality of America’s founding being built on the backs of the enslaved is not, then, some contemporary piety of the “woke”. Since Samuel Johnson acidly inquired “How is it that we hear the loudest yelps of liberty among the drivers of negroes?”, this founding contradiction has never been out of view.

In 1773, Benjamin Rush published a pamphlet asking the same question: “Where is the difference between a British Senator who attempts to enslave his fellow subjects in America, by imposing taxes upon them contrary to law and justice, and the American Patriot who reduces his African brethren to slavery contrary to justice and humanity?”

The same contradiction was perhaps most famously restated by Frederick Douglass: “What to the slave is the Fourth of July?”

The serious issue of whether race is just an unfortunate asterisk to the Declaration of Independence or whether it was formative to the creation of the Union is at the heart of what has morphed into the American history wars of the present moment. Its mirror image in the UK asks whether colonialism was incidental or fundamental to British economic and political power.

The organic relationship between history and freedom lies in the willingness of free states to accept a record of their pasts, stained with wickedness as much as heroism

Historians have had their say on both sides, but arguments from evidence have been sandbagged by politicians interested in making national allegiance rather than issues of economic and social equity the engine of electoral mobilisation. The result is to turn debate about what actually happened into a patriotic litmus test. Should history make you proud or ashamed? Unapologetically nationalist or penitentially iconoclastic?

But history is neither in the business of self-congratulation nor self-flagellation. History is in the truth business. And if the truth should be hard to nail down in simplicities, then the least history can do is to disabuse its readers of outright falsehoods. Thus history will tell you, in irrefutable documentation and direct witness, that millions of European Jews were systematically murdered by the Nazis.

Notwithstanding the history oration delivered by Donald Trump on July 4 2019 during the tinhorn parade of military hardware, there were no revolutionary war airports for the Continental Army to seize, nor did it deliver a “total victory” at Fort McHenry, that siege taking place in an altogether different war in 1814.

Supporters of former president Donald Trump stand near Confederate and US flags as they gather for his first post-presidency campaign rally last month © REUTERS

The truth indelibly and unapologetically imprinted in the Constitution of the Confederacy is that its rebellion was not fought merely for “states’ rights’’, as its apologists like to pretend, but to preserve humans as property.

Article IV Section 2 of that document plainly states that “no slave or other person held to service or labor in any State or Territory of the Confederate States, under the laws thereof, escaping or lawfully carried into another shall, in consequence of any law or regulation therein, be discharged from such service or labor, but shall be delivered up on claim of the party to whom such slave belongs”.

Likewise, while it is true that the Parliament of Great Britain did indeed abolish the slave trade in March 1807, Congress had actually done the same three weeks earlier. Britain liquidated the institution of slavery itself in 1834 but on condition that obscene sums of British taxpayers’ money would go to compensate former owners of the enslaved.

Come the Civil War across the Atlantic, the great majority of the British political elite, including Liberal Party leaders like Gladstone, whose family fortune was in cotton, cheered on the Confederacy. Vocal support for the Union was largely confined to radicals like John Bright and his constituency of factory workers in Lancashire.

History casts shadows as well as light. It always has. Resistance to vain self-regard has been its working principle ever since Thucydides made the climax of his epic work not an Athenian triumph, but the city-empire’s bloody comeuppance in the catastrophic expedition to Sicily.

A girl helps carry a US flag during a Fourth of July Independence Day celebration in Washington DC © REUTERS

The organic relationship between history and freedom lies precisely in the willingness of free states to accept a record of their pasts, stained with disaster and wickedness as much as heroism and achievement. Distorting the record so that it becomes an exercise in the genealogy of present glory is to corrupt its integrity. Best leave that to the dictators.

This is especially true of foundation myths. Fifteen years ago, in Rough Crossings: Britain, the Slaves and the American Revolution, I suggested (and I was by no means the first to do so) that the armed mobilisation of the southern colonies, its crossing of the Rubicon of separation, was, in large part, a response to fears of slave rebellions in the spring and summer of 1775.

Even before the governor of Virginia, Lord Dunmore, issued a proclamation promising liberty to slaves who joined the army of the king, alarm bells were being rung among Patriots that the unscrupulous British government would deliberately stir up both a slave insurrection as well as an armed movement of Native American tribes. No historians imagine this move was made out of the milk of humane compassion, but rather as a pre-emptive blow against the plantation economy of the rebels.

But British motives are not the point. Widespread fearfulness, close to panic, that a rising was at hand moved the colonial elites of Virginia and North and South Carolina to arm themselves, as much if not more, against an uprising of slaves and Indians as the redcoat soldiers of the king. This was what Jefferson meant when, among his exhaustive inventory of crimes attributed to George III, the future president claimed that “he has excited domestic insurrections among us”.

It has been one thing to maintain that the Civil War was fought over race, but quite another to argue that the same question was central to its founding moment in 1775-76. The New York Times 1619 Project, with its implication that race runs like a red thread throughout American history, from the Revolution to the Civil War on to the Jim Crow years and the fight for voting and civil rights, outraged those on the nationalist right who believe that the job of history is first and foremost an act of national self-affirmation.

The notion that radical professors have hijacked American history to brood punitively on matters of race led Trump to launch a 1776 Commission, whose report promising to keep the national chronicle mostly upbeat and sunny became public just two days before his reluctant exit from the White House. A number of state administrations of Trumpian kidney have sought authority to monitor curricula for their proper quota of unblemished patriotic pride: history as pom-pom waving.

Anger at the 1619 Project’s emphasis on race in the history of the revolution has not been confined to the political right. Major authorities on revolutionary history denounced it for what they called shoddy scholarship and distorted use of sources. But recent works based on deep research, in particular Robert G Parkinson’s Thirteen Clocks: How Race United the Colonies and Made the Declaration of Independence, as well as work by Alan Taylor, have produced an abundance of evidence to show unquestionably that, as Parkinson writes, “the glue that held [the Union] together was a shared fear of British agents working in tandem with enslaved and Native peoples to destroy them”.

My moth-eaten Union Jack carries a piece of this chastening history in its fabric. I acquired it from a junky antique shop in Shelburne, Nova Scotia, when researching the history of the enslaved who had believed the promises of the Crown enough to flee their masters and join its army in their thousands. There were Black soldiers on both sides in many of the American revolution’s battles, including the decisive engagement at Yorktown. But on the conclusion of the peace in 1783, Washington demanded the return of those former slaves to their owners.

To his credit, the last British governor, Sir Guy Carleton, refused, insisting that the promise of freedom would be honoured. More than 2,000 sailed out of New York harbour along with white Loyalists to Nova Scotia where, predictably, the land promised to them, including lots around Shelburne, was either withheld or reduced to the most uncultivable and rocky soil. Disenchanted though still legally free, many went with the young John Clarkson’s fleet to resettle in West Africa, in what became Sierra Leone.

The Nova Scotia flag is evidently of a later date but, when I unfurl it, the place and the history seem woven into its threadbare fabric and the picture of that surprising, sobering past comes alive in all its tragic complexity. Which is, rather than a pep pill for national happiness, what history most valuably yields.

Simon Schama is an FT contributing editor