Slavery and its legacies have never been far from the American political consciousness. The Boston town meeting called to protest against the British Stamp Act in 1765 passed a resolution calling for an end to slavery, so keenly did the protesters feel the contradiction between the much-talked-of rights of Englishmen and the colonists' enslavement of Africans. Once independence had been won, anti-slavery societies popped up everywhere—North and South. Taking seriously the natural-rights philosophy articulated in the Declaration of Independence, Northern reformers began agitating for the repeal of the state laws that had created property in human beings. A system of coerced labour which had been introduced into the British colonies with scarcely a murmur of opposition suddenly appeared like a stain, a blot on the escutcheon of the republican honour of the United States.

From the simple preamble to the Massachusetts state constitution to the intricate legislation providing for gradual emancipation passed in New York, Connecticut, and Pennsylvania, one by one, the Northern states found ways to end slavery in the years between 1780 and 1804, dramatizing as nothing else could have done the people's new legislative sovereignty.

This first emancipation movement gave thousands of self-liberating slaves a destination in their flight from the South, and laid the basis for America's free black population which tripled between 1790 and 1810. Despite vigorous opposition from slaveholders, what had earlier appeared impractical, if not impossible, was achieved. In states like New York, where one quarter of the labourers of Manhattan were enslaved persons, abolition represented the most peaceful intrusion on private property in the annals of self-government.

Signalling a sudden awakening from the slumber of thoughtless toleration, this outpouring of anti-slavery zeal in the North was an ominous development at a time when so few sentimental ties existed to bind the regions of the United States into a national union. Rid of the incubus of slavery, Northerners could take the moral high ground when events pushed the topic into public notice, as with the Haitian revolution or Congressional debates on fugitive slaves laws. Wary of such a contentious issue, national leaders promoted a live-and-let-live attitude towards Southern slavery, working out a series of intricate compromises whenever the subject came up. Better, they said, to concentrate the country's energies on bringing the continent under American dominion.

Ah, there was the rub. The westward movement of American settlers pushed to the fore the question of slavery's spread, especially after the Mexican-American War brought Texas and California into the union. By the 1850s, settlers were ready to move on to the land of the Louisiana Purchase—what Jefferson in 1803 had called the Empire for Freedom. The bearable friction of an earlier period became unbearable; every move in the struggle to bar new slave states added combustible material to the incendiary issue.

Abraham Lincoln hated slavery, but he loved the union more. Throughout his political ascent, he tacked before the winds of moral complacency, seeking a sure ground where he and the new Republican Party could stand. He found it in opposition to the expansion of slavery. Lincoln was a temporizer, but not a moral eunuch like his opponent, Stephen Douglas, who went about the country saying that he didn't care if the people voted slavery up or voted slavery down as long as they had a chance to exercise their “popular sovereignty”. Douglas successfully championed legislation which opened up the Territory of Kansas to settlement without the customary prohibition of slaves, putting at risk the successful containment of “the peculiar institution”.

William Lloyd Garrison, the fiery Abolitionist, hated slavery even more than he loved the union. He outraged crowds by burning copies of the US Constitution to demonstrate that any document that lent support to slavery deserved contempt. But much as he hated slavery, he confined himself to organizing anti-slavery militants through The Liberator and his public lectures.

John Brown, the historical figure at the centre of Russell Banks's new novel, Cloudsplitter, hated slavery, and he also hated temporizers. He barely tolerated Abolitionists, who only talked about ending slavery. For years, he and his sons risked life and limb, helping self-liberating slaves reach Canada through the so-called “underground railroad”.

Fanaticism does not travel well through time. The impulse to throw oneself in front of a train of evils speeding along the rough tracks of history comes to few. Reading about one such fanatic when the evil he stalked has long since hit time's dustbin does not immediately appeal, but Banks's storytelling powers are such that Brown's world slowly emerges, bringing with it an understanding of the moral milieu which nurtured his dreams and fortified his followers. In Cloudsplitter, Banks gives us the life of an avenging angel, and Old Testament prophet, and a monomaniacal terrorist, all rolled up into a vivid characterization of John Brown.

His Bible, read with avidity every day, opened up philosophy and literature to Brown as it closed off any other source of human understanding, its stories offering him practical wisdom, its observations a fund of moral precepts, most importantly the injunction to combat sin whole-soully. Brown was also a day-dreamer, a man whose fantasies plucked him out of the nineteenth century and threw him back into the age of fire-and-brimstone retribution.

In many ways, Brown was a typical Yankee—that stereotype parodied on the contemporary stage as Brother Jonathan, delivering endless cant in a nasal twang. An attentive provider, Brown worked assiduously as a farmer, grazier and tanner. A patriarchal family man, he fathered twenty children with two wives. Keen to prosper, he got caught up in the speculative mania endemic in antebellum America, even travelling to London in a hare-brained scheme to undercut British wool prices. Banks details all this, integrating the mundane with the apocalyptic, while sustaining the dramatic tension, as John Brown moves from conventional zealotry to an intensifying grandiosity.

Like the stereotype which hardens too fast and cracks, Brown broke the Yankee mould. He was too literal a reader of biblical vengeance to oppose slavery like a Garrison. The awestruck reactions of those who listened to his fervent denunciations of slavery played on his sense of his own destiny. Drawing his maturing children into his fantastic plans, Brown bided his time. When Kansas opened up, Brown and a number of his sons joined the band of migrating Northerners, many of them sent by the Massachusetts Emigration Society to swell the ranks of “free-soilers”. But the slow process of building up a democratic majority in Kansas tried Brown's patience. Enraged by the Missouri border ruffians who were harassing anti-slavery families, Brown went on the offensive with his own paramilitary force, conducting night raids of swift ferocity. Kansas became “Bleeding Kansas” and John Brown of Osawatomie a national figure. Emboldened by these successes, Brown concocted a scheme to seize the federal arsenal at Harpers Ferry, Virginia. From that redoubt, he would arm the hordes of slaves whom he imagined running to his sanctuary of freedom. Thus would he destroy Southern slavery, a far brighter prize than merely adding another free state to the divided union.

Brown emerges from the pages of Cloudsplitter as refracted through the memory of his third son, Owen. In the novel, an elderly Owen decides to scotch the legends about the John Brown who lies “a-mould'ring in his grave”. With a diarist's recall of dates and a therapist's penchant for analysis, Banks's Owen recapitulates his father's anti-slavery crusade from the vantage-point of the family he commanded. Cast by Banks as an Isaac to his father's Abraham, Owen is also trying to make sense of how his own young life got implicated in his father's bizarre plan to organize a mass exodus of slaves from a South neither of them knew anything about. One of five survivors of the Harpers Ferry raid—John Brown was executed—Owen is depicted as feverishly debriefing himself a half-century later, using the emotional and physical distance of his hermit's cabin in California to find the method in the madness of the 1850s. The result is a historical account of John Brown and his times, laced with the tormented self-accusations of the fictionalized Owen.

The hostility that American whites have shown to American blacks over four centuries has forged the strongest kind of racial solidarity in the United States, that based on a profound sense of difference. Banks makes Owen Brown's consciousness of this difference a dramatic pivot for his storyteller who reproaches himself for his awkwardness with free blacks and self-liberating slaves, knowing that his father—unique among antebellum Americans—did not share his discomfort.

Banks has succeeded well as a historian, a social critic and an evoker of the frontier landscape through which the Brown family came and went. But like the Cloudsplitter, John Brown, Banks asks too much of Owen, expecting him to be at the same time a credible witness to the family's domestic negotiations and spiritual mobilization, a window on to his father's personality, and a prober into his own psychic wounds. Russell Banks's Owen is not up to the task, but, as a simple narrator, he does provide access to one of the most emblematic actors in American history. And he answers the lingering questions about Brown's fanaticism in a way that satisfies both the critical and the curious.