by Sonia Shah
Many of the Irish famine refugees settled in the neighborhood named after the five-pointed intersection at its center and built atop the garbage-filled Collect Pond: Five Points.
Their arrival set off a housing boom. To accommodate the newcomers, property owners built haphazard additions atop the neighborhood’s original two-and-a-half-story wooden buildings. They built new houses in the backyards, crowding two or even three houses on twenty-five-by-one-hundred-foot lots. They converted stables into apartments and rented out attics and basements with windowless bedrooms too low to stand up in.12 When that didn’t satisfy demand for housing in Five Points, property owners started tearing down the old wooden buildings to make way for tenements: four- and six-story brick buildings specifically designed to cram as many people as possible inside. The first tenement had been built at 65 Mott Street in Five Points in 1824, jutting out above the buildings around it “like a wart growing on top of a festering sore,” as a local reporter put it. In the back lots, they built more tenements, of necessity just half the size of the front buildings. These “rear tenements” had no windows on the backs or sides, so the sole apertures looked out into the dim, privy-filled alleys between the buildings, festooned with lines of laundry. Some property owners even squeezed third tenements into their lots, or erected little shacks in the yards by the latrines.13
The economics of the housing boom contributed to the crowding. Property owners didn’t live in the dark, cramped domiciles they’d built. (Tenements were taller and deeper than the wooden buildings they replaced, so they were naturally darker inside, and owners rarely installed then available gas lighting.)14 Instead, they leased their tenement buildings to “sublandlords,” who ran saloons or groceries on the ground floors of the buildings and rented out the apartments. They earned a good living doing so, charging prices so high they routinely reaped a nearly 300 percent profit. But the high rents intensified the crowding, as cash-strapped tenants were forced to take on their own paying boarders to help cover the rent. Nearly a third of Five Points’ residents lived with boarders.15 In a typical tenement apartment on Cedar Street, a 144-square-foot room housed five families, sharing two beds among them.16
The most wretched of Five Points’ domiciles lay underground. More than eleven hundred people in the Sixth Ward that comprised Five Points lived in basements, including in cellar flophouses, where a bunk—specifically, a piece of canvas stretched between wooden rails—could be rented for 37.5¢ per week. New York’s doctors claimed they could spot basement dwellers by a glance at their pale faces and a sniff of their musty odor. It permeated “every article of dress, the woolens more particularly, as well as the hair and skin,” as one put it.
In the past, the poor had lived dispersed along the periphery of towns and villages. Five Points reversed that pattern, drawing them all together. Sex workers found the centrally located slum convenient for accessing clients. Poor people across the city found shelter in its broken-down buildings. With an average per capita income that was the lowest in the city, gangs, crime, and prostitution flourished. Slums like Five Points became what the anthropologist Wendy Orent calls “disease factories.” They could take a pathogen and whip it into an epidemic as ably as an engine combusted fuel into motion. And in Manhattan, the Five Points disease factory blazed not in some far-off, isolated locale but in the heart of the city.
City officials were only dimly aware of the health hazard that Five Points posed to the rest of the city. At one point, they considered razing parts of the neighborhood to build a prison. But they didn’t, out of fear that the unsavory locale would lead to outbreaks of disease among the inmates. Most outsiders treated Five Points as a detached spectacle, threatening to them mostly in terms of their moral sensibilities. Journalists and writers toured the neighborhood, in a trendy practice they called “slumming,” to pronounce their condemnation. (An echo of their disgust can be heard today, in the 2002 film Gangs of New York, directed by Martin Scorsese and based on a 1927 book about Five Points.)17
And so while commentators issued regular bulletins broadcasting their moral distaste (Charles Dickens called the slum “hideous” and “loathsome”), the crowds that would ignite a city-enveloping epidemic continued to grow. By 1850, in the slums of New York City, nearly two hundred thousand people crammed into each square mile. That’s nearly six times more crowded than modern-day Manhattan or central Tokyo, and over a thousand times more crowded than any group of humans had ever lived before.18
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After a seventeen-year absence, cholera returned to New York City in 1849 with a vengeance. The epidemic began, like many epidemics, with small, barely noticeable outbreaks on the outskirts of the city. In the winter of 1849, a packet ship called the New York arrived in New York harbor from Le Havre. Seven of the passengers had died of cholera during the journey. A city health officer hustled the ship’s three-hundred-odd passengers into a customs warehouse, turning it into a makeshift quarantine hospital. Over the following weeks, cholera sickened 60 and killed over 30 at the warehouse-cum-hospital. Unbeknownst to the rest of the city, 150 others scaled the warehouse walls, boarded small boats, and escaped into the metropolis.
In January 1849, cholera broke out in the city’s immigrant boardinghouses, possibly as a consequence of the infected escapees’ arrival. A lull of a few months during the winter followed. Then in May, cholera infiltrated Five Points. In rooms without running water where multiple families prepared food, ate, and slept together, the vibrio easily passed from person to person. Cholera stool clung to hands and splashed on shared bedding and clothes, which residents sold to ragpickers and washed at public taps. Like a hurricane hovering over warm waters, the epidemic gained strength.
Once the vibrio entered the groundwater, cholera exploded across the city. (Although piped water from unpolluted upstate sources had become available in 1842, two-thirds of the city continued to rely on the shallow public wells on the street corners.)19 The health department closed four public schools to use as cholera hospitals, casting schoolchildren out into the cholera-plagued streets. Dead bodies lay untended for hours and sometimes days before being picked up and taken to the potter’s field on Randalls Island, where they were deposited the same way they were in Paris in 1832, in wide, shallow trenches, one atop the other.
By the summer, President Zachary Taylor could do little more than call for a day of “national prayer, fasting and humiliation” to tame the city’s raging epidemic. Ultimately, more than five thousand would die.20
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By all rights, the urban experiment that began in the nineteenth century should have failed. By the middle of the century, writes the historian Michael Haines, big American cities had become “virtual charnel houses,” their primary demographic characteristic being high mortality. Deaths outnumbered births. Despite the greater availability of food and paid work, children under the age of five who lived in cities died at nearly twice the rate as those living in the countryside. In 1830, a ten-year-old living in a small New England town could expect to see his or her fiftieth birthday. That same child, living in New York City, would be dead before the age of thirty-six. If you plotted population density and early childhood mortality on a graph for the years between 1851 and 1860 in England and Wales, you’d see a straight line heading upward.21
Even those who survived suffered the price of urban living. Their poor health stunted their growth: the average height of West Point cadets born between 1820 and 1860, as the nation became more urbanized, declined by a half inch. The shortest recruits came from the most densely crowded cities. The same process of deterioration unfolded in Manchester, Glasgow, Liverpool, London, and everywhere else that crowded urban living took root.22
Industrial cities survived, like dying patients on life support, because new blood in the form of immigrants kept pouring in to replenish their diminished, dying masses. In the years after the 1849 cholera epidemic in New York, immigrants continued to stream into the city, at the rate of nearly t
wenty-three thousand every month. They were more than enough to replace the parade of corpses flowing out of the city.23
Meanwhile, new regulations on housing slowly eased the deadliness of the city. The crusading journalist and photographer Jacob Riis used the new technology of flash photography to capture images of the dark corners of the tenement world for an aghast public. His 1889 book How the Other Half Lives helped ignite a movement for tenement reform in New York City. One of the first reforms, the Tenement House Act of 1901, required that city buildings provide exterior windows, ventilation, indoor toilets, and fire protections.
Five Points, a neighborhood premised upon crowding, didn’t survive the era of housing reform. Much of it was simply demolished. A sliver of the old neighborhood became what is today Chinatown. Another, the site of the old Collect Pond, became a small paved park fenced with chain link, surrounded by imposing government buildings: Superior Court, City Hall, and the clinics of the Department of Health of the City of New York, among others. Passersby would never suspect that a riotous neighborhood of any kind once existed there.
The last vestiges of the slum were lost in the September 11, 2001, terror attacks, when 6 World Trade Center collapsed. The sole collection of artifacts from Five Points—eight hundred thousand fragments of porcelain, bone china, tea sets, tobacco pipes, cisterns, and privies that archaeologists had collected before the five-way intersection was demolished to make way for a courthouse in the early 1990s—had been stored in the basement.24
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Thanks to the housing revolution, even the most crowded cities can be healthful places to live. In general, people who live in cities today live longer than those who live in rural areas. Only a few health burdens remain—higher rates of obesity and more exposure to pollution, for example.25
And yet, as washed clean of their past as cities like New York may appear, the housing revolution they enjoyed, like the sanitary revolution, has been partial and selective. It hasn’t penetrated many of the poorer countries of the world, and its insights haven’t been applied to our livestock. In India, due in part to poverty and in part to a lack of governance, housing regulations are as sparse and poorly enforced as in nineteenth-century New York.
In Mumbai, the densest streets in slums such as Dharavi hold 1.4 million people in each square mile, more than seven times the concentration of humans packed into nineteenth-century Five Points.26 Rural migrants live on the street in shacks made of scrap metal and tarps. They cluster around the entrances of the city’s middle-class apartment blocks, like the one my cousin lived in. I remember one morning, some years ago, while sitting by the grated window of his flat drinking tea, hearing a loud whoosh followed by a cloud of dust and some commotion from the street. The narrow cement terrace on the floor above us had sheared off the building and plummeted to the alley below, reassembling itself into a mound of steaming rubble. My aunt and cousins marveled quietly for a few minutes at the destruction, with about the same amount of interest and lack of alarm as might be provoked by a crow that had grabbed someone’s toast.
Such scenes of urban decrepitude will become more common in the future, for the process of urbanization that began in the industrial era is accelerating. Back then, urbanization was rapid, but it was still exclusive: globally, more people lived outside cities than inside them. By 2030, experts estimate, that will change. The majority of humankind will live in large cities.27 Only a handful of these large metropolises will be as healthful and well regulated as the cities of Europe and North America. Many will be more like Mumbai. Two billion of us will live in slums like Dharavi.28 Our booming livestock population, which is larger today than the cumulative population of the last ten thousand years of domestication until 1960, live in the animal equivalent of slums, too. More than half of the world’s pigs and chickens are raised on factory farms, and more than 40 percent of the world’s beef is produced on feedlots, where animals are crowded together by the millions.29
The growth of slums is one reason why the 2014 Ebola epidemic was so deadly and long-lasting. Before 2014, Ebola outbreaks had never occurred in towns larger than a few hundred thousand. Four hundred thousand people lived in Kikwit, the Democratic Republic of Congo town that experienced an Ebola outbreak in 1995. Just over one hundred thousand lived in Gulu, Uganda, in 2000, when Ebola emerged there.30 Since these locales were relatively small and remote, experts widely considered the virus, as the title of a 2011 scientific paper put it, a “minor public health threat” in Africa.31
But then the virus spread into West Africa, where it affected a markedly different demographic landscape. Ebola struck three capital cities, with a combined population of nearly 3 million: Conakry, the capital of Guinea, on the west coast of Africa; Freetown, the capital of Sierra Leone, 165 miles south of Conakry; and Monrovia, the capital of Liberia, 225 miles south of Freetown. These are not cities full of spacious high-rise apartments equipped with Wi-Fi and all the latest mod cons. They’re overcrowded, haphazardly developed, and chaotic, as scores of news consumers finally learned when lurid photos of West African slums splashed across websites and newspapers during the outbreak.32
Crowds provide pathogens such as Ebola and others with at least three advantages. For one, they achieve a sharp uptick in their rates of transmission. When Ebola lurched out of Guéckédou and into the crowded capitals of Guinea and Liberia, its transmission rate spiked.33 (The same thing had happened to variola, the virus that causes smallpox, when it emerged in urban centers, and could happen to its cousin monkeypox if, as the ecologist James Lloyd-Smith speculates, it spreads into a city like Kinshasa in infected meat or in the bodies of infected people.)34
For another, pathogens can burn through these larger populations for much longer. Each of the twenty-one outbreaks of Ebola that preceded the 2014 epidemic had been contained within a few months. Ten months after Ebola struck West Africa and its bristling cities, not only was the epidemic not under control, it was still growing exponentially. More than three thousand were dead; over six thousand had sickened. “We have never had this kind of experience with Ebola before,” said David Nabarro, who was coordinating the United Nations’ response to the epidemic. The nature of the urban landscape spelled the difference. “When it gets into the cities,” he said, “then it takes on another dimension.”35
But the most transformative effect of crowds lies in the way they allow pathogens to become more deadly. This has to do with the peculiar evolutionary advantages that pathogens that infest crowds enjoy. Under most circumstances, virulence is detrimental to a pathogen’s ability to spread. Consider pathogens that spread when people breathe on each other, like influenza, or when they touch each other, like cholera or Ebola. Successful transmission depends on social contact between infected and noninfected people. Uninfected people must inhale the breath of the infected or touch their bodily fluids. If they don’t, the pathogen is stuck. It can’t spread.
This reliance on social contact makes virulence problematic for such pathogens. If they are highly virulent, their victims will sicken and perhaps even die. Infected people will end up alone in bed or isolated in hospital wards rather than at work shaking people’s hands or on the train breathing on other passengers. When infected victims die, their bodies will be abandoned, burned, or buried—possibly before the pathogens lurking inside can spread to anyone else. This is a serious disadvantage. And it’s why highly virulent strains are more likely than less virulent ones to die out. Virulence is evolutionarily constrained.
But certain human behaviors lift these brakes on virulence, allowing even the most deadly strains to flourish. One example is burial rituals that require the bereaved relatives to handle the corpses of their loved ones. A funeral tradition among the Acholi people of Uganda, for example, calls for corpses to be bathed by relatives and for their faces to be ritually touched by mourners. Similar rituals, which likely played an important role in the 2014 Ebola epidemic in West Africa, free pathogens from the debilities of virulence. Even
pathogens that promptly kill their victims, like Ebola does, can spread into new victims, because social contact continues even when infected people are dead.36
Crowds of people in slums and animals in factory farms do the same thing. In crowds, social contacts that spread pathogens continue even when victims are sick and dying. The sickbed is in the living room or the kitchen where friends and relatives have easy access to the ill. The hospital wards are full and beds crowded with several patients each, worried relatives hovering at their sides. Sick animals are crammed into cages with healthy animals. Under such conditions, pathogens that evolve to become more virulent suffer none of the debilities that virulence would normally exact. They can spread regardless of how ill they make their victims.37
They can be as virulent, in other words, as the most dangerous pathogens in the world: those that don’t rely on social contact to spread. These pathogens are either stable in the environment or are carried by vectors. They include killers like cholera; Mycobacterium tuberculosis, which causes tuberculosis; and variola, which causes smallpox. Virulence doesn’t handicap their ability to spread, because they can spread from their dead victims by persisting in the environment until another live victim picks them up. The same is true for vectorborne pathogens like Plasmodium falciparum, which causes malaria. So long as mosquitoes keep biting, the pathogens continue to spread, no matter how sick their victims become. (On the contrary, virulence might even improve their transmissibility, since sicker, bedridden victims may be more likely to get bitten by mosquitoes compared to less ill ones.)38
Pathogens that spread through social contact are usually destined to be relatively mild. Crowds allow even these pathogens to become killers.
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The way crowds make pathogens more virulent can be clearly seen in the case of influenza. In recent years, by providing the virus with large crowds of animals and people to infect, we’ve created a host of new, more virulent strains of the virus.
