Once upon a time (half a century ago), the leading professional association of American historians was called the Mississippi Valley Historical Association (MVHA). Its journal, the Mississippi Valley Historical Review was subtitled, modestly, “a journal of American history.” In 1965, the MVHA changed its name to the Organization of American Historians (OAH), but the OAH's journal (which became The Journal of American History) continues to wear the old association's badge: a steamboat. Old habits die hard.

But old histories do not. In the race for interpretive novelty that constitutes so much of the contemporary field of American history, few spare a thought for what that bygone association of “an” American history with the Mississippi Valley might tell us. And therefore, as the OAH tries to “internationalize” American history, it fails to notice how the name of its former professional self might stand not for a quaint folksy regionalism superseded by a national historical consciousness, but for a profoundly global conception of the continental heartland's economy and its place in the world. That economy, its obsessions and lusts, its demonic cruelties, and above all its manifold materializations—in “sun, water, and soil; animal energy, human labor, and mother wit; grain, flesh, and cotton; pain, hunger, and fatigue; blood, milk, semen, and shit” (9)—is Walter Johnson's subject. It is an economy sedimented so deep in the muck of the river that defines it that Johnson's remarkable labor of retrieval at first seems hopeless, akin to the Sisyphean task of a dredge: each bucket of filth brings to the surface the microscopic remnants of a thousand lives; each is but a fraction of what must be disgorged, coughed up, and written down. Simultaneously, it is sedimented in the ledgers of thousands of planters and merchants, factors and bankers, spread across two continents; column upon column of abstracted inky scratches. It is Johnson's genius to marry the muck to the scratch, and from that infectious combination to conjure the economic culture of the cotton kingdom, in all its viscous viciousness, and the precise trigonometry of its location in nineteenth century capitalism's world-wide “space of flows” (Giovanni Arrighi, The Long Twentieth Century: Money, Power and the Origins of our Times [2010], 81–85.)

We know how important cotton was in the economic history of the antebellum republic, because Douglas North told us in his Economic Growth of the United States (1961). After the fashion of the “skeletal” economic history that he championed, however, North gave little attention to the material realities of the cotton economy. He did not tell us how it was embodied. Historians of antebellum slavery had more to say on that score, but their subject was oddly decontextualized. It was slavery per se, not slavery as a capitalized labor process within a specifiable commercial economy built on the armed expropriation of vast swathes of territory, its spectacular speculative distribution, the obsessive, ruthless, cotton monoculture that followed, and the expression of all that in “a history of bare-life processes and material exchanges” (9). Nor did either economic historians or historians of slavery (with a few exceptions influenced by Eric Williams) take their task to be to embed the detail of the cotton kingdom's slave labor process in the world economy, to unravel the “network of material connections” (10) that lashed Louisiana to Lancashire.

Johnson has remedied all this, and much, much more besides. He has written the political economy of slavery in the Mississippi Valley as a historically specific instance of commercial capitalism, and as an agonizingly vile human relation; he has traced the multiple circulations of bodies and banknotes, of commodities and credit, of cotton and land and debt, from which that political economy was constructed; he has deconstructed the technologies of navigation that tied that political economy together; and he has explained how the naturalized national perspective of “American” history obscures the imperialist logic of the cotton kingdom's southward thrust toward the Gulf of Mexico, toward Cuba and the isthmus states, toward the Amazon Valley and the Pacific: new nineteenth century worlds for an endless expansion of the Mississippi Valley's slave economy.

Throughout, Johnson is committed to a deeply materialist history that approaches its subjects as elements in a “physics” (67) of interaction and motion. The commitment effects an unparalleled density of observation, binding into one historical narrative components that extend all the way from the “neuro-muscular transformation” (162) forced upon enslaved field hands by the micromechanical demands of the act of picking cotton, to the undersea hydrological currents linking the Mississippi to the Amazon that fated (in the mind of the oceanographer Maethew Fontaine Maury) South America to become an extension of the cotton kingdom. But in no sense at all is his assemblage of detail unwieldy. River of Dark Dreams has a fierce, elegiac beauty. It is written to settle an account, to straighten a crooked record, to forge a memory of such tensile strength that it can never again be broken. The pledge is apparent from the outset, in repeated epigraphic allusions to The Souls of Black Folk that render River of Dark Dreams an instantiation in explicit historical form of the “echo of haunting melody” that Du Bois heard “well[ing] up from black souls in the dark past.” Perhaps inevitably, such is that past, one senses an author at times driven to incredulity by what he is obliged to recount, by its “show and tinsel built upon a groan,” (46) by what Conrad (exploring another dark river) called the “touch of insanity.” At these moments, River of Dark Dreams—an intensely visual book—becomes history seen through Werner Herzog's lens, part Fitzcarraldo (1982), part (and especially) Aguirre, the Wrath of God (1972).

If Du Bois is one progenitor, Walter Benjamin is another. (The two have much in common, not least an awareness of the relationship between mourning and history.) Johnson's ferocious concentration on history's materiality is one indicator; its specific attention to what Benjamin refers to (in The Arcades Project) as “the economic facts” is another. The influence extends to larger representations: Johnson's New Orleans, for example, is much more than just a major commercial city. Once one reads the history of the Mississippi Valley as River of Dark Dreams proposes, not as a regional subtheme within something called “American history,” but as its own world historical constellation, New Orleans becomes (like Paris) a “capital of the nineteenth century” in all Benjamin's senses of the phrase.

River of Dark Dreams has much to offer the legal historian. I do not mean in the detail of its deployment of legal materials, although that deployment is as careful and as revealing as Johnson's research in general. What it has to offer, simply, is itself. It is a book of enormous learning and, no less, of sustained moral passion. It is unrelenting in its demands for the reader's attention, and it is profoundly worthy of that attention. It is an extraordinary work of history; one of the finest I have ever encountered. It is a book any historian would be proud to have written, and that all of us who wish to consider ourselves conversant with American history, however we define it, should feel obliged to read.