I bet few graduate students these days haven’t read, or at least seen referenced, Walter Johnson’s essay “On Agency.” Published a decade ago, the essay was prompted by what had become hackneyed trope in slavery scholarship. Everyone seemed to ascribe slaves a role in shaping their lives—“agency”—despite the power asymmetries inherent in the slave-master relationship. Johnson famously called for an end to this kind of writing. But one of his subtler points may have been lost amid his overarching argument. It wasn’t that slave agency was unimportant, but that it had lost its contemporary relevance. Finding agency mattered in the Civil Rights Era, the years in which the scholarship flourished, because it bolstered African Americans’ claims on the nation’s past, and thus its future.

But at the turn of the twenty-first century that imperative was less pressing. Therefore he pushed scholars to find new ways of writing about slavery that spoke to contemporary issues. Reading that essay in light of his new book, River of Dark Dreams, it seems clear that Johnson wasn’t just speaking to his colleagues. Indeed, the book reflects such a deep commitment to present concerns that one wonders if the book’s power, its undeniable urgency, will make it seem dated a generation from now. Every sentence, while only rarely referencing the present, seems freighted with contemporary allusions: to the crisis of global capitalism, to torture, to environmental degradation. One almost sheepishly hopes these problems persist if only to make this magisterial book required reading well into the future.

Several of the other contributors to this roundtable have already commented on Johnson’s interest in global capitalism. So I’ll avoid discussing that issue at length despite its obvious relevance for today. In any event, what I found most compelling was his interest in science, specifically his focus on the destructive power of technology. Read partly as a history of science, River of Dark Dreams is in fact up-to-date in more than one way. It’s both a cautionary tale against believing in technology’s all conquering powers, as well as a still too rare attempt to incorporate current themes in the history of science into the history of slavery.

Nowhere is this more evident than in Johnson’s focus on “the steamboat economy.” One of Dark River of Dreams’ key contributions is to challenge the meta-narrative of nineteenth century America, one defined by industrialization. This narrative almost inevitably centers on the North, taking inventions like railroads and factories as emblems of modernity. The South possessed neither of these inventions, effectively writing the region out of the nation’s history, as well as legitimizing the questionable assertion that slavery was a backwards, archaic institution. Johnson tries to put an end to this view. Up until the 1850s, the steamboat, he argues, epitomized modernization. Lowell had nothing on Louisiana: “a mere handful of steamboats docked along the levees in New Orleans on any given day could have run the entire factory complex at Lowell” (6).

Nothing evoked the idea of progress, the idea of modernity, more than this awesome new machine. And it was the South, not the North, that both monopolized steamboat technology as well as perfected it. But Johnson keeps his eye trained on the steamboat’s devastating environmental effects. The high-power steam engine Southerners invented required vast amounts of wood—and deforestation was the result. Year-round commerce necessitated the building of dams, trenches and levees, all of which eroded the Mississippi River’s natural flow. When technology failed and the steamboat engines exploded—which happened thousands of times, killing hundreds—or the levees broke—all hell broke loose. There is no mistaking the contemporary allusions, from Katrina and our dependency on oil, to the ocean spills and climate change that have occurred as a result. For Johnson, history still has lessons to impart.

Thankfully Johnson does not spell them out. Perhaps future readers, in say 2050, will not even recognize them. But some other present-day problems Johnson winks to have been with us at least since the birth of Newtonian science. One of them is the idea that science serves a symbol of civilization. A good deal of the scholarship on science focuses on the false hope scientific practitioners, and the societies that support them, placed in technology. It is not merely that people believed technology could solve all their problems, from bodily disease to societal ills, but that merely possessing certain kinds of technology functioned as a kind of self-justification of superiority.  Civilized people have technology; primitives don’t.  Or so the logic went (and goes).

Johnson imports this idea to the steamboat, arguing that the very language people used to describe this new technology—what he calls “the steamboat sublime”—helped white Americans justify the appropriation of Native American land, and ultimately their extermination. Everyone from swindling steamboat salesman to Mark Twain wrote of the steamboat in rapturous terms: it was a wonder, awesome, terrifying, powerful—and so too, by extension, were the men that invented it. In the age of the steamboat, the Indian and his canoe had no chance. They were “consigned,” Johnson writes, “to prehistory, the dead-time before history really began.” And so it was that the language of technology served as “a sort of alibi for imperialism and dispossession” (76-77).

Misconceptions about how scientific knowledge is produced—a key theme in the history of science—also finds an outlet in River of Dark Dreams.  Technologies are often assumed to be the inventions of brilliant scientists working in sealed off laboratories, far removed from the real world. But many science historians are at pains to show the messy, social interactions that actually produce scientific knowledge. In his section on agricultural practices, Johnson shows how slaves actually contributed to and possessed the true knowledge that led to profitable cotton production.

Meanwhile, his steamboat section illustrates that the high-power engine did not flow from the likes of a nineteenth century Steve Jobs holed up in his garage. The engine instead resulted from “a piecemeal process” (92): money-mad boosters were intent on creating a fast, cheap machine that could swiftly transport cotton upriver. The result was a steamboat that was inexpensive and quick, but also dangerous.  Any moment it could explode, and often it did. As is often the case in Johnson’s work, capitalism is the culprit. “Competition in the steamboat business spurred technological degradation rather than innovation,” he writes. “Danger was built into the boats” (122).

Even cotton—or rather, especially cotton in the slave South—embedded the illusion of scientific progress.  Southerners spent a vast amount of mental energy figuring out how to produce a profitable crop. Johnson’s chapter on the invention of a specific strain of cotton, Petit Gulf, demonstrates his absorption of—and challenge to—the history of science. He recycles the argument that slavery fueled a new kind of scientific racism, one that equated dark skin with people innately predisposed to physical labor. “The blacker the better” was stock advice to slave-buyers published in planter journals (160). Johnson’s analysis of the invention of the Petit Gulf seed is more novel: it flips on its head the relationship between man and nature historians of science typically stress.

Emphasis is usually placed on nature’s domination over man. But Johnson argues that when it came to the invention of Petit Gulf cotton, man had in one important way conquered nature. He managed to create an artificial plant perfectly suited to the size of the human hand. That helped build a frighteningly efficient plantation economy tailor-made to the bodies of slaves. “Bales per acre per hand” became the stock measurement for how much cotton a planter could produce at any given moment. Given cotton’s centrality to the world’s economy at mid-century, the implications are vast. The entire global economy was, in effect, being measured in the palm of a slave’s hand. Now here is a provocative new way of telling an old story. Slavery not only turned human beings into a price: the bodies of men, women and children were used to price commodities. That is a kind of agency, you could argue, but one far less heroic than tragic.