3 EVERYTHING YOU ALWAYS WANTED TO KNOW ABOUT GUANO BUT WERE AFRAID TO ASK

It is a little-noted feature of world history that in the past few decades, the map hasn’t changed much. Of course there have been trouble spots (Iraq/Kuwait, Russia/Ukraine, Sudan) and the dramatic dismantling of the Soviet Union. But there hasn’t been anything like the wrenching cartographic tumult of previous centuries: the invasions, revolutions, conquests, and annexations that turned Poland into a cursed accordion, madly expanding and contracting, and that wiped Indian Country off the map.

The tendency of today’s borders to stick in place can make the shapes of countries seem inevitable. The hexagon of France, the stilettoed boot of Italy, the impossibly thin needle of Chile (“a dagger pointed at the heart of Antarctica,” quipped Henry Kissinger)—though they were obviously the result of historical fortune, it’s difficult to imagine them taking forms other than the ones they did.

That’s one reason why it’s hard to remember the U.S. founders’ hesitations about westward expansion. Surely, we think, they must have seen how stunted, how unfinished their little stub of a country was. There’s something satisfying about following the story to its end, like putting together a jigsaw puzzle. The Louisiana Purchase, click, East and West Florida, click click, Texas, click, Oregon, click, the war with Mexico, click, and the Gadsden Purchase, a sliver of land on the Mexican border that filled out the familiar logo-map profile of the United States. Click. Picture complete, destiny manifested.

Except that the puzzle wasn’t finished. The logo-map silhouette accurately captured the borders of the United States for only three years. Because in 1857, not long after the Gadsden Purchase was ratified (1854), the United States began annexing small islands throughout the Caribbean and the Pacific. By the end of the century, it would claim almost a hundred of them.

The islands had no indigenous populations and, at the time, no strategic value. They tended to be remote, rocky, and rainless—poor places to grow things on. But that didn’t matter. They had the one thing that everyone in the nineteenth century badly wanted. They had “white gold,” known in less polite circles as bird shit.

To understand why anyone would care about bird droppings, it helps to know a little about preindustrial agriculture.

Farming in the nineteenth-century United States was not like it is today, acres of staggeringly prolific fields bristling with high-yield crops. It was a touch-and-go business. The reason Benjamin Franklin’s population numbers had alarmed Thomas Malthus was that Malthus couldn’t see where the food would come from to feed those multiplying generations. New farmland and virgin soil had given North Americans a margin of ease, he acknowledged, but that could only be temporary. In the end, he wrote, “the power of population is so superior to the power in the earth to produce subsistence for man, that premature death must in some shape or other visit the human race.”

As the nineteenth century progressed, agricultural scientists got a better sense of why land fertility lagged behind human fertility. Arable land contains nutrients, without which plants will not grow. The most important by far is nitrogen, one of the four building blocks of life (CHON: carbon, hydrogen, oxygen, nitrogen). Soil short of it yields underdeveloped plants with pale leaves and protein-poor seeds.

Luckily, nitrogen makes up nearly four-fifths of the earth’s atmosphere by volume. Unluckily, atmospheric nitrogen is almost exclusively dinitrogen (N₂), whose strong triple bonds render it unreactive and thus inaccessible to plants. Worse, nature offers frustratingly few ways to turn dinitrogen into a usable reactive compound. Lightning will do it, as will the bacteria that inhabit the nodules of the roots of some legumes, but that’s it.

It took chemists until the nineteenth century to piece all that together. But farmers, in their own way, had comprehended it for millennia. All agricultural traditions, in order for them to last long enough to be traditions, require methods for managing nitrogen flows. These are intricate ballets between farmer and earth, choreographed by folk wisdom and danced to the rhythm of the seasons. Nitrogen-rich manures are spread, crops rotated, forests burned, fields left fallow, or lentils planted. Each locale offers its own complicated variation on an enduring theme.

These complex systems faltered, however, in the nineteenth century. Industrialization required raw materials to feed the factories and grain to feed the workers. Farms that used to grow a rotating variety of crops for local consumption started focusing on the most profitable crops and grew them for distant markets. Who has time to plant beans when the British are buying cotton at eleven cents a pound and the ships are waiting?

Worse, by delivering the produce of the countryside to distant cities, the new agriculture broke the age-old cycle that had restored waste—human and animal—to the land, returning nitrates to the soil. Nineteenth-century agronomists cringed at the thought of large cities flushing into rivers and oceans the nitrogenous wastes that could have fertilized the fields. The author of a much-used textbook estimated the annual value of “lost” human feces to be $50 million, which approached the size of the federal budget.

These were not idle worries. Single-crop farms yielded diminishing returns. “Soil exhaustion,” as it was called, was the bugbear of nineteenth-century agriculture throughout the industrializing world, and it had taken hold of eastern farms. “The fact is notorious,” reported an agricultural expert to the New York Senate, “that there are thousands, if not millions, of acres in this State which once bore 20 bushels of good wheat per acre, that now yield not more than ten.”

Farmers scoured their areas for organic material that could be spread on their fields to replenish them. The sheer variety of possibilities discussed in Sir Humphry Davy’s authoritative Elements of Agricultural Chemistry (1813) gives some sense of how desperate they’d become. Davy considered rapeseed cake, linseed cake, malt dust, seaweed (“as fresh as can be procured”), straw, spoiled hay, oats, “mere woody fiber,” “inert peaty matter,” wood ash, “the entire parts of the muscles of land animals,” putrefied animal remains (horses, dogs, sheep, deer, and “other quadrupeds”), fish, blubber, bone dust, horn shavings, hair, woolen rags, “the offals of the tan-yard,” blood, “scum taken from the boilers of the sugar bakers,” coral reef, sea sponges, fresh urine, “putrid urine,” pigeon dung, chicken dung, rabbit dung, cattle dung, sheep dung, deer dung, and soot.

“Poudrette,” a polite name for human feces sold commercially, was of special interest. Even Victor Hugo couldn’t run his harried hero Jean Valjean through the sewers of Paris in Les Misérables (1862) without pausing—pausing, indeed, for a whole chapter—to remark that it really would be better if some use could be found for Paris’s waste. In a section regrettably cut from the musical, Hugo outlined his plan for “a double tubular apparatus, provided with valves and sluices,” to carry it back to the fields.

Large-scale fecal repatriation remained the stuff of fiction, though. City feces were too dispersed and heavy to collect and transport, and few of the other “soil amendments” lived up to their reputations.

What did work was guano. That term can refer to any bird or bat feces used as fertilizer, but the guano on everyone’s minds was the nitrogen-rich droppings of cormorants, boobies, and pelicans on the Chincha Islands off the coast of Peru. Islands make attractive rookeries for seabirds in general. The Chinchas had the additional virtue that they hardly ever saw rain. The guano piled hundreds of feet high and baked in the sun, so that the very rock of the islands was centuries’ worth of calcified bird droppings.

Guano was noxious, “a beastly smelling-bottle sort of mess, looking like bad snuff mixed with rotten kittens,” as a Vermont paper put it. Virginia’s senator deemed it “the most odious and disagreeable material that can be imagined.” Its sharp, ammoniacal smell was notorious, perceptible from miles off. Sailors hauling guano could spend no more than fifteen minutes belowdecks with it. They would emerge gasping for breath, sometimes suffering nosebleeds or temporary blindness.

**Late nineteenth-century sheet music celebrating the Age of Guano**

And yet, sprinkled in small quantities over the nitrogen-parched farms of North America, the stuff worked miracles. The first ships carrying Peruvian guano arrived in the 1840s and quickly sparked a mania. It was, crowed the Cleveland Herald, the “cheapest, most powerful, enduring, and portable fertilizer” of all. Tall tales spread, about the father who locked his ten-year-old son in a barn with a pile of guano and unlocked it hours later to discover a full-grown man in his place, or the farmer whose guanoed cucumber plants shot out of the dirt and seized him with their vines.

Peruvian guano may have been miraculous, but it wasn’t free. Rabid demand drove up the cost. So did the tight control of the supply by British firms that monopolized guano exports from the Chinchas and kept prices high.

This was, to put it lightly, a problem. The “guano question” came up again and again in Congress. (“This subject is of much less importance than the Pacific railroad,” protested a weary California senator. “The Senator has not paid attention to the use of guano, or he would not make that remark” came the curt reply from Virginia.) Guano prices also appeared in four presidential annual messages, most notably in Millard Fillmore’s first. “Peruvian guano has become so desirable an article,” Fillmore said, that he regarded it as the “duty of the Government” to secure it at a “reasonable price.” “Nothing will be omitted on my part,” he promised the nation, in the quest for cheap guano.

Those were not empty words. In 1852 Fillmore’s secretary of state, Daniel Webster, gave speculators carte blanche to sail to the guano-laden Lobos Islands off the coast of northern Peru and scrape them clean, promising naval protection and dispatching a warship for that purpose. It was a bold yet dangerous plan, as Peru claimed sovereignty over the islands. In response to Webster’s move, Peru prepared for war. One Peruvian paper called on its readers to rise up and “exterminate the hated race,” to seize U.S. property and “kill before Peruvians should be killed.”

Cooler heads soon prevailed, and the United States backed down (“The Peruvian penguin has fairly beaten the American eagle,” chortled The London Times). But what was clear is that guano had nearly triggered an inter-American war. Nothing guaranteed it wouldn’t do so in the future. Just a single Peruvian island, one of Delaware’s senators intimated, would be worth more than the Gadsden Purchase, Cuba, and all the rest of the Caribbean combined.

Luckily, there were other ways around the British monopoly. A few years after he finally finished his Leatherstocking saga, which had done so much to cement the mythology of Daniel Boone, James Fenimore Cooper wrote a new novel, The Crater (1847), about a guano island in the South Pacific. In the novel, a “vast deposit of very ancient guano” washes down onto the island’s plain, which obligingly erupts forth in “verdant glades.” Discovering this, a band of travelers from the United States form a colony there. A small, volcanic rock halfway to Fiji was perhaps an unexpected place for Cooper to stage the sequel to his tales of westward expansion, but guano had magnetic lure.

And not just on Cooper. Speculators, too, suspected that unclaimed Pacific islands contained untold guano riches. Two such islands, Howland and Jarvis, in the Central Pacific, more than a thousand miles from the nearest large landmass, had been known for decades to whalers and seemed particularly promising. Guano entrepreneurs hastily formed the American Guano Company, with a capitalization of $10 million (a number that grows more impressive once you realize that all federal expenditures in 1850 totaled less than $45 million). They begged President Franklin Pierce to send the navy to Howland and Jarvis to protect their diggings from foreign interlopers.

Pierce not only obliged, he went one better by backing the Guano Islands Act in 1856. Under its terms, whenever a U.S. citizen discovered guano on an unclaimed, uninhabited island, that island would, “at the discretion of the President, be considered as appertaining to the United States.” It was an obscure word, appertaining, as if the law’s writers were mumbling their way through the important bit. But the point was this: those islands would, in some way, belong to the country.

Perhaps the lawmakers were right to mumble, as this was a significant departure from the past. At every other stage in U.S. history, territorial expansion had been contentious, debated in newspapers and fought over in Congress. Now, if the law passed, any random adventurer would be “at liberty to tramp about the Pacific, or any other ocean, and annex islands to the United States,” as one paper put it.

Members of Congress hesitated: this was a “new kind of legislation” with “consequences beyond the mere supply of guano.” Senator William Henry Seward, who had sponsored the law, sought to assuage his colleagues’ doubts. If the bill had allowed the “prospect of dominion,” he acknowledged, they might be right to question it. “But the bill is framed so as to embrace only these more ragged rocks … which are fit for no dominion.” James Fenimore Cooper’s fantasies aside, Seward promised that there would be no “establishment of colonies” on the islands.

That was all Congress needed to hear. The bill passed, and speculators scrambled to stake their claims. It was another land rush, this time in the Pacific and the Caribbean. The first batch of islands were added to the United States in 1857. By 1863, the government had annexed fifty-nine islands. By the time the last claim was filed, in 1902, the United States’ oceanic empire encompassed ninety-four guano islands. “The Pacific will be ours, and the Atlantic mainly ours,” crowed Walt Whitman. “What an age! What a land!”

James Fenimore Cooper, knowing of guano’s unparalleled fertilizing powers, imagined his fictional island to be a “little paradise.” He could not have been more wrong. What Cooper had failed to grasp is that guano accumulated only in extremely dry climates, oceanic deserts where the lack of rainfall allowed bird droppings to collect for centuries. Such islands were barren rocks, not fertile plains—unpromising sites for human habitation.

Still, the guano didn’t hop onto the ships by itself. Guano mining—tunneling, picking, and blasting the stuff loose and hauling it to waiting ships—was arguably the single worst job you could have in the nineteenth century. It offered all the backbreaking labor and lung damage of coal mining, but to do the job, you had to be marooned on a hot, dry, pestilential, and foul-smelling island for months. Respiratory diseases, causing workers to pass out or cough up blood, were common. So were gastrointestinal ailments—the unsurprising consequence of crowded conditions, rotten food, and a dearth of fresh water. Clouds of shrieking seabirds darkened the skies overhead, unleashing the occasional fecal rainstorm (“We were completely encased in a thick film of bird manure,” one visitor remembered). On Howland Island, an out-of-control rat population scurried underfoot, adding yet another vile ingredient to the epidemiological stew.

Finding workers wasn’t easy. Peruvian guano lords, unable to recruit their compatriots, relied mainly on Chinese laborers, whom they lured onto eastbound ships with false promises or sometimes simply kidnapped—between 1847 and 1874, at least sixty-eight of these ships mutinied. U.S. guano speculators gathered their workforce principally from Hawai‘i, where, it was felt, the workers (called “Kanakas”) would have some affinity for the landscape. “These patient, hardy, dark-skinned Kanakas who dig and handle the guano, and play the toilsome oar through boiling surf from sunrise to sunset, under the glare of an equatorial sun … are a remarkable race of people,” wrote one appreciative employer, though he seemed most impressed by their ability to endure hardship, survive disease, and brave the perilous waters to procure fish. “The shark and the Kanaka are on the friendliest terms imaginable,” he noted.

The worst of it was on the other side of the globe, on the tiny Caribbean island of Navassa, near Haiti. Rather ominously, it was called Devil’s Island.

Although Navassa didn’t have much actual guano, its coral reef was packed with deposits of tricalcium phosphate, the fossilized legacy of centuries’ worth of marine life—also a rich nutrient for exhausted soil. Under the control of the Navassa Phosphate Company, this would prove to be the most reliable source of fertilizer in the United States’ budding island empire.

For workers, the Navassa Phosphate Company used African Americans from Baltimore. Promising a tropical life of picking fruit and romancing beautiful women, the company induced the often-illiterate workers to sign long contracts and step on board.

Yet once the workers disembarked, they found conditions considerably less idyllic. The scorched, jagged, sea-battered island had neither fruit nor women. Instead, it offered a scurvy-inducing diet of hardtack and salted pork, along with the company of abusive white overseers. Such necessities as shirts, shoes, mattresses, and pillows could be got only from the company store at wildly inflated prices. Workers who fell ill were fined. Those who made trouble were “triced”: tied up for hours in the hot sun with their arms in the air and their feet barely touching the ground.

In 1889 an argument between an overseer and a worker exploded into violence. White officers fired at their workers, who fought back with axes, razors, clubs, stones, discarded pistols, and dynamite. Five white officers died in the melee. A nearby British steamer picked up the remaining whites and took them to Kingston (“We have been treated like princes from the very moment of our rescue,” read the satisfied report). The workers were hauled back to Baltimore and marched through the cold streets, cuffed and in some cases shoeless, to the city jail.

With five white corpses to account for and lurid testimony from the surviving officers filling the papers (THE BLACK BUTCHERS ran one semi-hysterical headline), the defendants’ prospects did not look good. Black activists in Baltimore raised funds and hired a formidable legal team, including E. J. Waring, the first black lawyer to pass the Maryland bar.

Waring and his colleagues pointed to the obvious: the wretched conditions and tricing of disobedient workers. But the case ultimately hung on a Hail Mary legal defense. The rioters could not be convicted, their lawyers argued, because the United States lacked jurisdiction. They pointed out that Haiti, too, claimed Navassa. They noted the absence of any U.S. official stationed there. And they probed the curious language of the Guano Islands Act, by which the islands were said to “appertain” to the United States. Appertain? What, exactly, did that mean? As the defense saw it, Navassa was foreign soil.

**Navassa rioters: Six of the Navassa Island defendants**

This was more than an attempt to win freedom for the rioters. It was a challenge to the legality of U.S. empire, and it made its way quickly to the Supreme Court. The court sided with the prosecution, affirming that U.S. law “unequivocally” extended to Navassa. Still, the defense had a point. If this was U.S. territory, where was the government?

President Benjamin Harrison wondered the same thing. He had little doubt that the rioters were “American citizens” who had been working “within American territory.” Yet he worried that the Navassa Phosphate Company had turned part of the United States into its own corporate fiefdom, governed not by law, but by corporate regulations.

In a remarkable turn, Harrison sent a warship, the USS Kearsage, to investigate—not the typical Gilded Age response to a workers’ uprising. When the Kearsage’s officers reported that Navassa was being run as “a convict establishment,” though without a prison’s “comforts and cleanliness,” Harrison’s sympathies tipped toward the rioters. He commuted the death sentences of the leaders and raised the issue in his annual message. “It is inexcusable that American laborers should be left within our own jurisdiction without access to any Government officer or tribunal for their protection,” he said.

It was a thundering presidential endorsement of a principle that had until then remained nebulous. No matter how remote those shit-spattered rocks and islands were, they were, in the end, part of the United States.

The story of the guano islands may seem trivial. After all, how important could a few dozen uninhabited islands be? Yet the guano craze of the nineteenth century left three legacies, all of which would shape the fate of the Greater United States.

The first was legal. The Guano Islands Act, the Supreme Court’s ruling, and President Harrison’s backing of that ruling collectively established that the borders of the United States needn’t be confined to the continent. In 1889–90, when the Navassa controversy was in the news, this was a minor concern. But in the decades to come, it would be the foundation for the United States’ entire overseas empire.

The second legacy was strategic. The same features that made the islands attractive rookeries for seabirds made them, decades later, desirable sites for airfields. The pointillist empire that the United States built after the Second World War would rely in part on those nineteenth-century guano claims.

The third and most immediate legacy was agricultural. In all, speculators scraped some four hundred thousand tons of rock guano off of U.S. appurtenances. That fell short of speculators’ wildest hopes, but it was nevertheless a significant haul.

Guano didn’t solve the soil exhaustion crisis, but combined with Chilean sodium nitrates, which companies started selling later in the century, it held it at bay. Mined fertilizers kept industrial agriculture sustainable long enough for scientists to devise a more permanent solution: manufacturing fertilizer from the unreactive N₂ in the atmosphere.

The breakthrough came in 1909, when Fritz Haber, a German-Jewish chemist, developed a technique for synthesizing ammonia, a nitrogen compound. By 1914, the experimental technique had become industrially viable, and in that year Haber’s method, called the Haber–Bosch process, yielded as much reactive nitrogen as the entire Peruvian guano trade. The difference was that Haber–Bosch, unlike guano mining, was infinitely expandable. It also didn’t require scouring the seas for uninhabited islands.

In a single stroke, Haber had opened the floodgates for the virtually unlimited growth of human life. The Malthusian logic was repealed. Soil exhaustion ceased to be an existential threat; you could just add more chemicals. Without Haber–Bosch, the earth could sustain, at present rates of consumption, only about 2.4 billion people. That is well under half of today’s population.

By inventing ammonia synthesis, Fritz Haber became arguably the single most consequential organism on the planet. The toll on his personal life, however, was heavy. His wife, Clara, was herself a promising German-Jewish chemist, indeed the first woman ever to receive a doctorate from the University of Breslau. Local women had crowded there to see her get her degree—“seldom has the awarding of a doctorate been attended by so many,” reported the newspaper. But after her marriage, Clara had abandoned her research and become a hausfrau, dedicating her life to supporting Fritz.

It was a Picture of Dorian Gray marriage: the more Fritz flourished, the more Clara withered. Just as her husband was honing his invention, Clara wrote an anguished letter to her former scientific mentor: “What Fritz has gained in these last eight years, that—and even more—I have lost, and what is left of me fills with the deepest dissatisfaction.”

Fritz had gained quite a lot. His invention won him the directorship of a new institute in Berlin and a central place within the German scientific establishment (a position he used to promote the career of a gifted young Jewish physicist named Albert Einstein). When World War I erupted, Haber volunteered his services. He suggested that the ammonia now pouring out of German fertilizer plants could be repurposed as explosives to bolster Germany’s dwindling munitions supplies. Since the war had cut Germany off from imported nitrates, this was an essential contribution. The president of the American Chemical Society calculated that Germany would have lost the war by early 1916 had Haber not replenished its stocks of nitrate explosives.

Nor did Haber stop there. He assembled a supergroup of German scientists, four of whom, like he, would go on to win Nobel Prizes. Overseeing their efforts, he introduced his second great invention: poison gas.

Not only did Haber invent it, he personally supervised its debut in 1915, releasing four hundred thousand tons of chlorine gas upwind of some Algerian troops at the Battle of Ypres. In a delicious historical irony, the man who saved the world from starvation was also the father of weapons of mass destruction.

For this, Haber won still more honors: a military commission, the Iron Cross, and an audience with the emperor. The only one who didn’t appear to be celebrating was Clara. Right after gassing the Algerians at Ypres, Fritz returned home for a quick visit. What transpired between husband and wife during that visit is lost to history, but after Fritz went to sleep, Clara went into the garden with his service revolver and shot herself in the heart. The next day, Fritz returned to the front.

There is great interest in Clara today, especially in Germany, where she is celebrated as a martyr to science. No note from Clara survives, and Fritz refused to speak about the subject, so it is impossible to say with certainty why she killed herself. Surely, she had many reasons. But the timing of her suicide and some of the testimony from those who knew her have led many to interpret it as a protest of her husband’s invention.

If it was, it was a prescient act. After the war, Fritz continued his work, and his institute developed a promising insecticide called Zyklon A. In slightly modified form, under the name Zyklon B, it would be deployed on Fritz and Clara’s fellow Jews, though this time not on the battlefield, but in gas chambers. Clara’s relatives were among those who died in the camps.

Luckily, not all of them perished. Although Clara’s married name was Haber, she is today known by her maiden name, the name under which she defended her dissertation: Clara Immerwahr.

Her cousin Max was my great-grandfather.