Liberty's Exiles, By Maya Jasanoff

Did anyone ever literally believe that God speaks English? One suspects not. But there are those who think the Goddess of Liberty does so, even if it was the French who first erected statues for her. There is a smallish but noisy transatlantic group of writers, politicians and think-tankers dedicated to the conviction that the values of freedom and democracy have their birthplaces and natural homes peculiarly – maybe even only – in what some of them call the Anglosphere. That term was popularised in 2004 by James Bennett, with his book The Anglosphere Challenge. It has been taken up by conservative historians like Niall Ferguson and, more stridently, Andrew Roberts, and by groups like the Social Affairs Unit. For a time, especially in the years of the Blair-Bush axis, it seemed to have some friends in very high places.

The supposedly innate affinity between the English language – or countries where it dominates - and the spirit of liberty is variously explained. Some have traced its roots back to medieval England's social structure, as Alan Macfarlane did in his 1978 book Origins of English Individualism – a work which, like Ferguson's and Roberts's relevant tomes, was damningly criticised by many specialists but won a wider circle of admirers – or even to the Anglo-Saxons before they fell under the "Norman yoke" in 1066. There were those who interpreted it in racial terms: a line of argument not today much favoured. Indeed, some propagandists for the Anglosphere's special virtues now seek to include India, and are already drawing grand conclusions from the fact that so many pro-democracy protestors across the Arab world seem to be fluent in English.

The most popular arguments, though, come from political history. They look – sometimes together, sometimes in contention – at Magna Carta, the growth of English Parliaments, the British upheavals of the 1640s and/or the North American ones of the 1770s. In the US, naturally, the last is the most favoured reference-point. And although the legacies and meanings of the American Revolution have also always been contested – perhaps never more so than now, when Tea Party activists take not only their movement's name but much of its message from a very particular understanding of what it was all about – the combatants all agree that the ground over which they fight is that of a claim to freedom.

It follows that the Loyalists of Britain's North American colonies, who fought to keep the connection with Britain, were enemies of freedom, diehard reactionaries. Mainstream, and especially mass-media, versions of American history long caricatured them when it didn't simply ignore them.

The latter habit predominated. Loyalists were almost erased from history: the enemies American patriots fought were depicted as Redcoats sent out from Britain, rather than – as they so often were – their own neighbours. There was a kind of entrenched denial of the evident fact that the "War of Independence" was also a civil war.

That view always stumbled over numerous awkward facts, not least the revolutionaries' behaviour towards Native Americans and enslaved Africans. Few serious historians have adhered to it in decades. Certainly Maya Jasanoff has no time for it in this book on "the loss of America and the re-making of the British Empire". Her American War of Independence does not pit freedom-loving patriots against Tory Loyalists, but sees two rival – and, in their own ways, equally coherent and credible - conceptions of liberty, and identity, in conflict.

Set against the American patriots' Spirit of '76 was a "spirit of 1783", which held that not only the rule of law and the rights of property but an ideal of individual freedom were best protected and pursued under the sheltering hand of the British Crown and Empire. At least a fifth, maybe a third, of the white colonists took that side, while thousands of slaves grasped eagerly at the British promise to free those who fought for them. Numerous Indian peoples (most prominently the Creek and Mohawk) quite rationally decided their best prospects lay in taking the British Crown's side.

Many who felt thus – about 60,000, though only a minority of the former Loyalists – went into exile. They scattered right across the British imperial world and sometimes beyond it: to Britain itself, and to what became Canada, but also to India, the West Indies, Australasia, South Africa and, for a substantial contingent of former slaves, to Sierra Leone.

The story of their diaspora is the heart of Jasanoff's book, told through a combination of broad-based global survey and detailed individual and family narratives of displacement. Nobody before has traced those stories in all their remarkable diversity and global reach, nor perhaps so fully brought together American, British, Atlantic and imperial histories for this subject, or in quite this way. Jasanoff's main text flows easily, at times almost novelistically, but her dense endnotes reveal the impressive breadth of her reading and the strength of her story's scholarly underpinnings.

Jasanoff's thinking about the character of America's revolution is by contrast fairly familiar territory; while the narrative device of seeking to portray a historical big picture through selected life-stories is also by now very established – perhaps a little too frequently deployed. On these levels Liberty's Exiles is certainly a less innovative work than Jasanoff's first, Edge of Empire, where she mapped the often bizarre world of imperialists' mania for collecting antiques and curios.

Still, this is both an intellectually impressive and a compulsively readable work. The book may seem as if it has almost everything – impressively wide-ranging scholarship, wonderful stories, world-historical significance, memorable characters. There is, though, sometimes a sense of opportunities missed. Jasanoff doesn't fully develop the ideas about political ideology and identity, theories of empire and nationhood, to which she alludes.

Doing so might have made for a slightly less entertaining book, but one of greater intellectual weight. Even her key phrase "spirit of 1783" to describe the complex of political ideas held by many Loyalists, too often repeated, is too little explored. She says disappointingly little about the specific roles of Scots and Irish (mentioned only in passing), or even Germans and Dutch, among American colonists and the Loyalist diaspora.

There is also, perhaps surprisingly, very little on the contemporary implications of her story, and how it relates to the many other stories told about "1776 and All That". If half the life, the vibrancy and never-ending appeal of history comes from the stories of the people involved, in their own times, surely another big part is how people – historians, politicians, indeed almost everyone – use it and fight over it today. Jasanoff largely misses out all that. Her book cries out to be read together with another, more present-minded recent work which touches on many of the same themes: Jill Lepore's The Whites of Their Eyes: The Tea Party's Revolution and the Battle over American History (Princeton University Press). As Lepore's work – or the ideological posturings of the Anglospheroids – suggests, Jasanoff's subject is more vigorously, even vituperatively, alive than one might know from her treatment of it.

Stephen Howe is professor of the history and cultures of colonialism at Bristol University