A truly singular architect of fictional worlds, across 30 years as a novelist Sebastian Barry has deliberately mounted a gallery of legendary and lost people who must ask, as his latest narrator does, “How big are we in the world?”

His work has long followed and developed hints about his own ancestry on both his father’s side (the McNulty novels, beginning with The Whereabouts of Eneas McNulty) and his mother’s side (the Dunne novels). Each vivid character is “a scrap of humanity like a million others”, which Barry patchworks to populate silenced histories, all those “great lengths of time leaving no trace”.

His new novel, The Newer World, is the third in a sequence of roiling stories that explore ever more expansive ideas of kinship and lineage, all set in the bond-breaking cauldron of 19th-century America. In Days Without End, Barry offered the tale of Thomas McNulty, filling out a sweet, queer dance card for his rumour of an ancestor who had fled the famine in Sligo to fight in the American Indian Wars. In two follow-ups, Barry is harmonising a choir around the flights and fears and occasional freedoms of his own blood, adding resistant indigenous and black voices to his career’s cumulative panorama of a personal Irish diaspora.

The narrator of his new book, one Tennyson Bouguereau, appeared as a formerly enslaved minor character in both Days Without End and A Thousand Moons, more of a marksman than a man, hailed as a singer of old songs. Here Bouguereau speaks to us from about 1900, mounting “an assault on what happened” over the 60 years that have led him to a state of awestruck perplexity.

Set near Paris, Tennessee (you’ll think of Wim Wenders, maybe, but America is lousy with Parises), the first part is a murder ballad. One can only flinch at the novel’s opening chronicle of lynchings, rapes, “guns and watchfulness”, which set us on what we and Tennyson expect might be a path of revenge. Instead, “a weird, peaceful massacre” will take place in concert halls around the world.

A Newer World felt somewhat vaporous on my first read, but actively resolute about irresolution on my second

Bookended by brutality, the heart of The Newer World is its middle section in which Tennyson joins an unnamed version of the Fisk Jubilee Singers, the black choir that began performing near the end of Reconstruction and, as African-American sociologist WEB DuBois put it, “sang the slave songs so deeply into the world’s heart that it can never wholly forget them again”. He tours England and Europe (though, surprisingly, doesn’t make the Singers’ historical visits to Ireland).

Barry won the Walter Scott Prize for Historical Fiction for a second time for Days Without End. But these books are more the heirs of Mark Twain and his denunciation of Walter Scott in Life on the Mississippi. It was “the Sir Walter disease”, Twain thundered, that had given an entire class of slave-owning rapists the tools to cosplay as knights and hooded saviours of their economy’s mock-ancient virtue.

Scott’s historical romances “had so large a hand in making Southern character … the inflated speech, and the jejune romanticism” that Twain laid the civil war as the outcome of plantations drunk on medievalist history novels. Barry is lyrical but not inflated, and he strips all chivalry from the picture: after emancipation, Bouguereau charges, “They wanted to worry us.” “It pleased them to take it back.”

Time moves strangely in the disarming, dreamy trance of this novel. “A year can feel like a long thing to live through, but afterwards, afterwards, what is it?” asks Tennyson. “It has only the thickness of a snowflake.” But snowfall makes a land of whiteness, and there’s a coyness and evasion to the narrator’s voice that sometimes seems to insist too strongly on the centrality of unknowing.

Barry’s emphasis on Tennyson’s naivety and shock – on surviving a “life without information” – gives us a good, sad man caught in history’s undertow: a beautiful literary creation, but that same profile can read as a refusal to credit Tennyson with his own agency, uncomfortably close to the old lies that Reconstruction failed and that freedom dreams were both given and revoked by whites.

At last, tragically, Tennyson follows one part of his divided heart and becomes a kind of Ulysses in reverse, seeking a home in the military as a refuge from the bewilderments of voyaging as a craft. A Newer World felt somewhat vaporous on my first read, but actively resolute about irresolution on my second: Barry is concerned with “aftermath” as something besides a name for devastation. The book thrums with memories of incomplete states, thinking about absolution, oblivion, reparation, affection. As Tennyson avows, “to sing soft is a great art”.

Greg Londe teaches Literatures in English at Cornell University