IN HYDROLOGICAL TERMS, the Mississippi was something of a freak. It was a titanic volume of ungoverned water flowing across a floodplain of very slight declivity. There were no mountain valleys to funnel it, or deep channels dug in the bedrock to keep it in place. It was traversing a flat and infinitely malleable surface of mud, silt, and clay—and this meant that it was free to move however and whenever its currents shifted.
Its basic form was an endless series of sinuously unfolding horseshoe curves, technically known as meander loops. The exact mechanism by which meander loops are created is still imperfectly understood, but it’s believed that the primary force shaping them is the natural tendency of flowing water to fall away from a straight line. The water in a meander loop actually requires far less energy to keep moving, even though it is covering so much more territory, than water traveling through a rigorously ruler-straight canal.
Meander loops tend to form in even equidistant patterns, all other things being equal, but at any given moment their pattern on a particular river usually appears to be wildly irregular. This is because the loops are continually being reshaped by a process of fluid dynamics called helicoidal flow. Helicoidal flow is a secondary type of turbulence that forms around the main current moving in a river channel. Two things happen because of helicoidal flow: the water along the outer curve of a meander loop speeds up and eats into the riverbank, and at the same time the water on the inner curve slows down and deposits the silt that it’s already carrying downriver. The result is that the outer bank is worn away while the inner bank is built up, and so the loop becomes inexorably larger and more pronounced within the same area of land. Sooner or later, the growing curves of adjoining loops touch, the current breaks through the banks, and a new connection is formed. On the Mississippi, these connections were known as cutoffs. When the main volume of the current flows through a cutoff, the silt being carried downriver begins to be deposited around it, building up new banks on either side, and the now-landlocked curve of the loop outside the new banks either dries up or else becomes a bayou or an oxbow lake.
On the Mississippi, where the land was flat, the current was vast and strong, and the helicoidal flow was perpetually at work, the meander loops and cutoffs were constantly unfolding into strange new contortions. In the lower valley, where the obstacles were the fewest, the Mississippi bent, doubled back on itself, executed hairpin turns, and twisted around to flow in new directions. A complete map of its meander belt, as the term is, would show that over the centuries the river had writhed around its current route like a nest of anacondas.
At ground level, this shifting tangle was experienced as an unending challenge. Whenever the river people gathered, all they’d ever talk about was how the river was changing. They’d rattle on in a whole specialized technical vocabulary of homegrown hydrology that described the river’s peculiar 'margin-top:3.6pt;margin-right:0cm;margin-bottom:3.6pt; margin-left:0cm;text-align:justify;text-indent:12.0pt;line-height:14.4pt'>The talk was a way of bonding; it enabled total strangers to chatter on together like childhood friends. But it was also an immediate practical necessity. The waywardness of the Mississippi was a constant threat. Every day, somewhere along the river, huge bluffs were collapsing; overgrown banks were falling in on themselves; ancient stands of trees were sliding down into the tide. Sandbars were growing into islets. Islets were accumulating rocks, rotted logs, and mud and sprouting with countless scattered seeds; they were bristling with new trees and underbrush; they were melting away in the current again and turning back into sandbars. On every voyage, the familiar landmarks were disorientingly reshaped or abruptly erased, while new hazards had popped up out of nowhere.
This was another big reason why there were no trustworthy maps of the river. It changed too quickly. Every pilot had to have his own mental map, which was added to, corrected, erased, and redrawn in his head on every run; and no two pilots’ maps, if they could have been compared, would have been identical. The river remade itself every day. People who lived on or around the river learned to think of it as untrustworthy, violent, deceptive, and unknowable. While the voyageurs called it the wicked river, the plantation slaves called it Old Devil River, because of its habit of playing bizarre and malicious tricks. A man would go to bed on one side of the river and wake to find that it had changed course overnight and his property was now on the opposite bank. That was not a simple matter, because the river was the boundary line between states: if he went to sleep in a slave state, he might wake in a free state, and he’d find that all his slaves had automatically been emancipated. This was why some people came to call it the abolitionist river—“abolitionist” being a worse insult than “devil.”
The most dramatic erasures and remakings of the river course happened in the floods. The floods were annual events. The upper Mississippi would freeze over during the winter; in early spring, the ice would break up and come grinding and tumbling downstream in thunderous cascades; and then in the following weeks, as the meltwater of the North Country came pouring down through thousands of tributaries, the river would rise. Since there was no quick way of getting news downriver, until the advent of the telegraph in midcentury, there were never any warnings about how high the river was running in the upper valley or how bad a flood season the lower valley could expect. The news from upriver arrived at the same speed as the flood itself. People could only wait it out and hope for the best; they’d simply have to watch each day as the waters inexorably crept up over the banks and drowned out their land.
Some of the Indians in the lower valley liked to say that the river was a snake that woke from a doze every seven years and lashed out at anyone foolish enough to live alongside it. As an average for the catastrophic floods—the floods that swept away whole towns and inundated the land for thousands of square miles along either side of the banks—seven years was about right. Sometimes these floods came more often. There were five catastrophic floods on the Mississippi between 1809 and 1816. There were four in the 1820s. There were only two in the 1840s—but the flood of 1844, one of the first for which there is any kind of hard data, is still the greatest volume of water ever recorded descending the river.
The floods were the great given of river life. Everyone who lived on or near the river had to learn to coexist with them somehow. Houses were built on stilts all through the swamps and marshlands; at St. Louis, the warehouses of the dock district had to be set so far back from the riverbank to protect them from the rises that there was a separate hauling fee to get goods carried off the boats into storage. Farmers working the bottomlands and transient river islets—unbelievably fertile lands, because of the topsoil that the floods dumped on them—would spend their winters building colossal rafts, so that when the river began to rise in the spring, they could herd their cattle and pigs and horses into pens, and load their grain and gear into makeshift barns, and then tie a rope to the tallest tree branch they could find and ride out the next weeks or months till the river dwindled again. They could only hope that their land was still there when the waters retreated. Often their homesteads ended up on the river bottom.
The highest water usually came in June. Everywhere along the river, people waited for the June rise the way they might await the results of a horse race. Some years the river rose only a few feet and swamped the fields adjacent to its banks; other years it rose ten feet or more and drowned the countryside. In 1844 it rose fifty feet and spread out more than ten miles wide and more than thirty feet deep in the central valley all summer long. At its height, the citizens of St. Louis gathered at the levee, as though at a regatta, and watched as Illinoistown on the far bank was wholly engulfed and its pieces carried off by the flood.
On June 5, 1805, at around one in the afternoon, a tornado came out of the hill country south of St. Louis and crossed the Mississippi. It was, according to one nineteenth-century writer, “the most violent tempest that ever visited Illinois.” That area of the Illinois shore was still only thinly populated and there were no reported fatalities, but the tornado brought down countless trees as it crashed through the old-growth forests of southern Illinois. The track of the storm went on for hundreds of miles; some said it went on all the way through to Indiana and even to Ohio—which would have meant it was on the ground for several hours, making it the most powerful tornado on record. For decades afterward, travelers making their way through the wilderness country of southern Illinois were stymied by a natural barrier, a wall of titanic fallen trees a mile wide and hundreds of miles long, rotting and moldering in the forest depths.
This is what routinely stunned visitors and new settlers: the violence and unpredictability of weather in the river valley. It wasn’t just the deep freeze of the northern winters, the flooded springs, or the mosquito-swarming summers; it was the daily calamity of the storms. Soldiers in the tallgrass prairies reported being caught in freak thunderstorms, which they called downspouts—presumably what meteorologists now call microbursts—where the rain came down so heavily they had to steeple their hands over their noses to go on breathing.
Even an ordinary spring thunderstorm could be perilous. The journalist Thomas Bangs Thorpe described one. He and a few companions were being led by an Indian guide through the wild country along the wooded bluffs on the east bank of the river when they saw a big storm billowing up over the hills on the far shore. The only shelter they could find was in a crude log cabin on the riverbank that had been abandoned by its previous inhabitants. The storm hit toward sundown, and it grew steadily worse as the evening went on. The rain was pouring in through the chinks in the logs; Thorpe wrote that they “were soon literally afloat.” A lightning strike a few hundred yards from the cabin set a huge oak ablaze, and soon the entire stand of trees that surrounded the oak was burning. The fury of the rain turned the fire into a tumult of steam, and the illumination of the lightning falling on the river was so strange that it seemed to Thorpe like something out of the book of Revelation. The river had, he wrote, “a smooth but mysterious looking surface that resembled in the glare of the lightning, a mirror of bronze, and to heighten this almost unearthly effect, the forest trees that lined its most distant shores, rose up like mountains of impenetrable darkness, against clouds burning with fire.”
As the storm raged on, Thorpe’s companions fell asleep. Thorpe was baffled by their cavalier attitude; he sat sleepless while the sound of their snoring added to his misery. Then sometime toward morning the Indian guide touched him on the arm and gestured for him to listen. Thorpe could hear nothing other than the roaring and drumming of the rain. The Indian suddenly jumped up and headed for the door. That woke one of Thorpe’s companions, who immediately grabbed for his rifle and demanded to know what was going on. “River too near,” the Indian said. Thorpe’s companion listened for a moment, and then shouted, “He’s right, so help me. The banks of the Mississippi are caving in.”
They made it out just in time. “The Indian was the last to leave the cabin,” Thorpe recalled, “and as he stepped from its threshold, the weighty unhewn logs that composed it, crumbled, along with the rich soil, into the swift-running current of the mysterious river.”
Even when there were no great events, no land-remaking floods or apocalyptic storms, the sheer scale of the river could be treacherous. Sometimes the issue was the river’s titanic lulling sameness, its vast, silent, and unhurried flow day after day: boats often came to grief for no other reason than that their crews simply couldn’t stay alert any longer. And when something did go wrong, it would suddenly become blindingly clear just how far one was from any help. A sudden squall or a swell could knock over one of the little braziers the crews kept lit on the deck and within moments the cargo could be set ablaze, or the horses or the cattle could have been panicked into a stampede—and even on the most crowded stretches of the river, the nearest boat was likely to be hundreds of yards away, bobbing along in the current hopelessly out of reach.
The scale of the landscape, too, created its own dangers. Settlements were still thinly spread; if a voyageur had his foot crushed by a loose barrel, he could have gangrene by the time the boat reached the next town with a doctor. Along most of the river the banks were still wholly wild, and going ashore there for any reason was perilous. There were large predators roaming along the riverbanks, bears and panthers and wolf packs; and there were human predators as well, Indian hunting parties and river pirates and armed settlers who didn’t like strangers. Lighting a fire was a major risk, for the adversaries it might attract—but in most of the country to go without a fire was even worse: the nights in the North Country could be punishingly cold, and in the South the mosquito swarms were so thick that they could drive people to madness.
The prairies of the central valley were probably the trickiest places to go ashore, because they seemed so simple: just treeless seas of grass spreading out evenly across a gently rolling terrain. They were easily passable in the spring, when the grasses were new, and in the autumn, when the grasses had died and had been burned off by the prairie fires. But in the summer the grasses grew more than ten feet high and offered no landmarks of any kind. Anyone who ventured more than a few feet from shore would become hopelessly disoriented in their rushing, sighing depths, broken only by the crisscrossing tracks left by the grazing deer. People were known to take hours or days to get back to the riverbank after thrashing around helplessly in the interior; inevitably there were stories about the unlucky wanderers who never did get back and whose skeletons weren’t found till the grasses dwindled in the fall.
But the greatest danger was the river itself, even when it seemed the most placid. A simple fall overboard could be fatal. The gigantic volume of the current caused complex forms of turbulence in the deep waters that were invisible on the surface, strong vortices and long trailing undertows that could suck down the hardiest swimmer. As one writer noted, “It is said that nothing that ever sunk beneath its muddy surface was known to rise again.” But the worst danger for a man overboard was the temperature of the water. Since the river was fed by meltwater tributaries in the Far North, even in high summer it could be bitterly cold. The slow-moving waters in the shallows were warmed by the sun and could at times become almost tepid, but the main current remained hidden in the darkness beneath the immense murky weight of the river and never got much above freezing. Anybody who was drawn down into the river depths for more than a few minutes would most likely succumb to hypothermia.
This was why a man overboard was generally considered a man lost. Even if the rest of the crew noticed in time that he was floundering in the water, there usually wasn’t much they could do for him; the boats couldn’t be turned around against the force of the current, and most were too unwieldy to be maneuvered quickly into shore—assuming the crew was willing to try. The truth was that most voyageurs took for granted that anybody who went into the water at all was doomed, and they usually wouldn’t bother to try throwing out a line. And anyway drowning was probably the most merciful way to go. A man who did manage to make it to shore found himself in a deserted and inhospitable country, perhaps hundreds of miles from the nearest settlement. He was soaking wet and blue from the cold, and with no way of building a fire, he would likely be dead of exposure by morning. The last sight he would get of his boat, it was gliding impassively downriver and vanishing around a bend for good.