In the year 1542, a traveler stopped on a high mound above the confluence of two rivers and listened to a silence that had lasted for more than a century. Below him lay the ruins of Cahokia, just across the river from modern-day St. Louis. Twelve or fifteen pyramids of packed clay, soft-shouldered against the sky, rose from the bottomland, the largest nearly a hundred feet tall.

The earth had grown over with prairie grass, and there was no one left. The Hernando de Soto expedition, the first Spaniards to push that deep into the continent, passed through the same decade without even noticing the mounds. Cahokia had been abandoned for over 150 years. Yet for nearly four centuries before that, it had been the largest city in what would become the United States, bigger than London or Paris at the same time.

At its peak around the year 1100, somewhere between 20,000 and 40,000 people lived in Cahokia and its surrounding towns. They built earthen pyramids, played a stone disc game called chunkey, and traded copper from the Great Lakes for shells from the Gulf of Mexico. They watched the stars, wove cloth, and ate remarkably well. The question of how they ate, and how the millions of other indigenous peoples across the continent ate in the year 1500, is one of the most misunderstood chapters of American history.

The popular image of pre-Columbian North America is of wandering hunters trailing bison on horseback, surviving on meat and little else. Almost none of that is true. At the moment Columbus reached the Caribbean, the majority of indigenous peoples in what is now the United States got most of their calories from plants they had grown themselves, plants their ancestors had domesticated and refined over thousands of years. The mounted bison hunter of the Great Plains existed only because the Spanish brought the horse to the continent after 1500.

Before that, there was not a single horse anywhere in North America. There was, instead, farming on a scale and with a sophistication that European visitors struggled to describe. There were towns of 3,000 people in northern New Mexico continuously farmed since the 1100s, corn fields stretching for miles along the Missouri River, managed oak forests in California, salmon weirs in Washington, and clam gardens in British Columbia. The foundation of all of this was maize.

Eight thousand years ago, a wild grass called teosinte grew in a valley in central Mexico with a handful of tiny, rock-hard kernels that could barely be eaten. Over generations, farmers, most likely women, saved seeds from plants with slightly larger, softer kernels. By the time Columbus sailed, maize had been bred into more than 200 varieties, adapted to specific elevations, rainfalls, and growing seasons. The Mandan on the cold Missouri River grew a corn that matured in only 60 days.

The Cherokee in the warm southeast grew a tall, slow variety that took half the summer. Maize crossed the Rio Grande around 4,000 years ago, reached the Mississippi Valley by roughly 3,000 years ago, and by the year 900 had become a true staple across the eastern woodlands. Around the year 1000, Cahokia exploded into being on the strength of corn. But corn by itself is a trap.

It is calorie-rich and easy to grow, but it locks away niacin in a chemical bond the human body cannot break, and it lacks the amino acids lysine and tryptophan. A population eating nothing but untreated corn eventually suffers from pellagra, a disease that cracks the skin, fails the stomach, and kills. When European countries began feeding American corn to their peasants in the 17th century, pellagra erupted across northern Italy and southern Spain like a plague. It never happened in Mesoamerica, never in the Pueblo villages, never at Cahokia.

Somewhere between roughly 1500 and 1200 BC, an unknown cook discovered the solution. The best guess is that it began by accident: a pot of dried corn boiled with an ember from the fire, or a cracked pot relined with wood ash that turned the water alkaline. The next morning, the corn had transformed. Its tough outer skin slipped off, the kernels were softer and sweeter, and the people who ate that corn thrived while others sickened.

The process, boiling corn in an alkaline solution of wood ash or limestone water, was passed from mother to daughter, from village to village, northward across the continent. The Aztecs called it nixtamalization. Without it, the corn-based civilizations of the Americas would never have existed. It was a chemistry trick that European scientists would not understand until the 1930s.

In the forests east of the Mississippi, the Haudenosaunee, whom the French would call the Iroquois, grew the three sisters together in the same mound. Corn was the elder sister, tall and proud. Beans climbed the corn stalk, returning nitrogen to the soil. Squash spread low, shading the ground, smothering weeds.

An acre of three-sister gardens could feed five people for a year. When the Pilgrims stepped off the Mayflower in 1620, half of them died the first winter. The next spring, a Patuxet man named Tisquantum, remembered as Squanto, taught them to plant corn deep with a fish buried under each seed, and beans among the stalks. That lesson almost certainly kept the Plymouth colony from disappearing.

Across the eastern woodlands, the forests themselves were managed. Indigenous peoples used carefully controlled fire for thousands of years to keep the understory open, encouraging berries and nut trees and drawing deer and turkey into hunting zones. The open, park-like forests that early Europeans marveled at were not natural. The American chestnut, which dominated the Appalachian forest until a blight wiped it out in the early 20th century, fed entire communities.

A single mature tree could drop two to three hundred pounds of nuts in a good year. The Cherokee had at least four words for different stages of chestnut preparation. On the plains, the Missouri River villages of the Mandan, Hidatsa, and Arikara were the grocery store of the northern plains. Their women tended vast gardens of corn, beans, squash, and sunflowers, and the fields belonged to them.

A man might hunt all the bison he wanted, but his family still went hungry in February if his sisters and mother and aunts had not raised a good crop. They raised so much surplus that every summer Cheyenne, Crow, and Sioux parties came to trade dried meat, hides, and knives for sacks of dried corn and beans. The famous horse-mounted, tipi-living bison hunters of the plains only existed for about 150 years, from roughly 1750 to 1900, after horses arrived from the Spanish Southwest around 1700. Before that, many of those tribes were farmers themselves.

The bison hunt on foot was its own remarkable feat. At a site in southern Alberta called Head-Smashed-In, hunters drove herds off a sandstone cliff for nearly 6,000 years, leaving a bone layer over thirty feet deep. A single bison weighed almost 2,000 pounds, and a herd of thirty or forty animals had to be processed before the meat spoiled. The women butchered, the men hauled, and strips of meat were laid on drying racks.

What they made was pemmican: dried meat pounded to powder, mixed with hot rendered fat and dried berries, and packed into sealed rawhide bags. It would keep for ten or twenty years without refrigeration. A one-pound bag could feed a working man for a full day. It was the answer to the great question of any non-agricultural diet: what do you eat in the middle of winter when the bison are scattered?

You eat the summer hunt. In the Southwest, the Pueblo peoples farmed a desert that received less than ten inches of rain a year. The Hopi planted corn twelve to fifteen inches deep to reach buried moisture, built stone check dams across dry washes, and terraced hillsides. They developed a blue corn whose first leaf could push through nearly a foot of soil.

At Acoma, a pueblo on a mesa in what is now New Mexico, people have lived in the same stone and adobe houses since at least the year 1100. By any normal definition, you should not be able to farm a desert. They did it, on the same fields, for more than a thousand years. Beyond the Sierra Nevada, in California, the indigenous peoples had built an entire civilization without farming.

They managed the land, burned it carefully, pruned oaks, and controlled deer, but they did not plant fields. They depended on acorns, which in some communities provided more than half of all calories consumed in a year. The problem was that acorns are full of bitter, slightly toxic tannins. The solution was leaching.

Women ground the acorns on bedrock mortars, some of which are now several feet deep, then poured water slowly through the flour for hours, draining the tannins away into sand basins. The resulting flour was cooked into a thick mush by dropping fire-heated stones into a watertight basket, or baked into loaves. The acorn woodlands of California were one of the most carefully tended food systems on the planet. Up the wet coast into the cedar forests of Oregon, Washington, and British Columbia, people lived on salmon.

Millions of fish came up out of the Pacific every year, so numerous that early observers said you could walk across a creek on their backs. At Celilo Falls on the Columbia River, families built wooden platforms over the white water and scooped salmon out of the air with long-handled dip nets. The right to fish from a particular platform was inherited like a deed; some had been used by the same family for ten generations. The catch was split, hung on cedar racks, and smoked over alder fires into hard sheets that would keep for two years.

The river also gave eulachon, a small oily fish so rich that it could be dried and burned like a candle. Its rendered oil, called grease, was packed into wooden boxes and traded hundreds of miles inland along the famous grease trails of British Columbia. A box of good eulachon grease was worth more than most things in life. In the Arctic, the Inuit and related peoples thrived on a diet that was almost entirely animal: seal, walrus, whale, caribou, Arctic char, and berries in the brief summer.

A successful bowhead whale hunt could feed a village of 200 people for a year. The whale was understood to give itself willingly to a hunter who had prepared properly and honored the right ceremonies. The diet provided everything the human body needs: vitamin C from raw caribou liver and whale skin, fiber from the partially digested plant matter in caribou stomachs, and abundant healthy fats from sea mammals. Before contact, Arctic peoples had almost no heart disease, almost no diabetes, almost none of the cancers Westerners suffer from.

By every metric, it was one of the healthiest human diets that has ever existed. The trade routes carried all of this across staggering distances. A woman in a Mandan earth lodge might have copper from the Great Lakes, dried fish from the Columbia River, and obsidian blades from the Rockies on her dinner blanket. A bag of pinyon nuts from Nevada could travel 2,000 miles to be eaten in a Cherokee town in present-day Tennessee.

Pre-Columbian North America was not a continent of isolated tribes. It was an interconnected, multilingual, deeply commercial world. What changed all of this was disease. Smallpox, measles, influenza, typhus, and other illnesses moved faster than the Europeans themselves, traveling along the same trade routes that carried pinyon nuts and obsidian and salmon grease.

Within two generations of first contact, the population of the Americas may have fallen by as much as 90 percent. The cities were already gone by the time the French missionaries paddled down the upper Mississippi in the 1670s. The mounds were covered in trees. Most of the knowledge built up over 5,000 years, the field rotations, the seed varieties, the cooking subtleties, died with the people who held it, often in villages no European ever entered.

What survived survived because women kept teaching daughters even when there were almost no daughters left, because elders kept telling stories even when there were almost no people left to hear them. What you eat today is in part what they kept. If you have ever eaten a tortilla, you are eating a Mesoamerican invention, nixtamalized for thousands of years before any European saw a corn kernel. If you have ever eaten pumpkin pie, you are eating a squash domesticated in what is now Mexico more than 9,000 years ago.

The potato came from the Andes, the tomato from Mexico, the peanut, the avocado, the cacao bean, the vanilla, the sunflower oil. Three out of every five food crops grown in the world today come from somewhere in this continent. The Native Americans did not simply help feed the early colonists.

The entire world eats today in large part because the cooks and gardeners of pre-Columbian America did the work first.