Humboldt and the Changing Canal Calculus

Ever since the Panamanian isthmus became a global route for conveying Peruvian gold and silver to Atlantic ships during the sixteenth century, those searching for a natural maritime passage had pondered the possibility of creating an artificial one. Eventually, the Spanish government developed a road-and river-based transportation network that connected the oceans. Not until 1814, on the eve of independence of the Spanish Latin American colonies, did the crown manifest interest in cutting a canal from the Caribbean to the South Sea (as the Pacific Ocean was often called).2

Foreign institutions such as the French Academy of Sciences had raised the isthmian canal issue during the Age of Enlightenment, but the person who put the project on the agenda of nineteenth-century world leaders was Humboldt. “The Philosopher” (as the front page of the New York Times memorialized him on the one hundredth anniversary of his birth) is well known to historians of science and postcolonial scholars as a pioneering biogeographer and critic of environmental mismanagement by the Spanish Empire.3 Because artificial waterways have a long history of disrupting ecological and social communities, his lifelong advocacy for a project as damaging as an interoceanic canal seems at odds with his reputation today as a “bracingly contemporary” prophet of the Anthropocene.4 In fact, it demonstrates how taken for granted the idea of improving the environment via massive civil engineering works was (and in some contexts, still is).

Humboldt achieved worldwide fame through popular accounts of his travels and studies of geography, geology, astronomy, meteorology, and ecology, among other fields. A large inheritance enabled the thirty-year-old mining inspector to finance his own scientific expedition to the Americas from 1799–1804, for which he convinced the king of Spain to issue him and his partner rare passports. Although he did not visit any parts of the isthmus south of modern-day Mexico, Humboldt’s access to maps, letters, and engineering reports in the archives of the Mexican viceroyalty and other Spanish territories provided crucial information about potential routes for a large artificial waterway.5 He discussed the issue in three best-selling books spanning four decades: Political Essay on the Kingdom of New Spain (1811); Personal Narrative of Travels to the Equinoctial Regions of America (1826), which contained the most detailed analysis; and Views of Nature (1849). Until his death in 1859, Humboldt endeavored to persuade the European and Latin American powers to overcome what he deemed their baseless concerns and invest in “a communication between two seas, capable of producing a revolution in the commercial world.”6

Which part of the New World would best accommodate a ship channel uniting the Atlantic and Pacific Oceans? In the Political Essay, Humboldt described nine routes or, as his translator put it, “points” for cutting a canal. Five spanned the Latin American isthmus, at Tehuantepec (Mexico), Nicaragua, central Panama (which he broke down further into three pathways), and two sites in northwestern Colombia designed to utilize the Atrato River, which flows north into the Caribbean Gulf of Darién (one route connected to the Pacific Cupica Bay and the other to a rumored artificial waterway further south known as the lost Raspadura Canal).7

Humboldt lamented the failure of previous explorers to apply a rigorous scientific approach to the physical geography of these regions. In particular, although the fifty-mile route from the Caribbean to the Bay of Panama had “occupied every mind” since Vasco Núñez de Balboa’s crossing in 1513, fundamental questions remained about the elevation of the cordilleras and whether the oceans on either side were of different levels. As he exclaimed in his interdisciplinary way, “These are problems whose solution is equally interesting to the statesman and the geographical naturalist!”8

Humboldt revisited the issue in the sixth volume of his Personal Narrative, for which an English translation appeared in 1826. By that time, most of the Spanish colonies in the Americas had gained emancipation, and the governments of the newly independent nations spanning the isthmus were beginning to explore the prospects of canal construction.9 In addition, the state of New York in the northeastern United States had completed in just six years a 363-mile-long barge canal between Lake Erie and the Hudson River. The Erie Canal connected the Atlantic port of New York City with the upper Great Lakes, and rapidly recouped its cost. For Humboldt, upstate New York’s artificial river provided an impressive example of the ability to open up trade and overcome the enormous expenses of excavating mountainous terrain.10

Despite his dismay that statesmen and merchants still lacked the geodetic data needed to make the right choice about the isthmian waterway’s location and magnitude, Humboldt did not let the lack of evidence stop him from stating his opinions.11 Of the five routes, he declared, “The isthmus of Nicaragua and that of Cupica have always appeared to me the most favourable for the formation of canals of large dimensions, similar to the Caledonian canal,” the fifteen-foot-deep waterway across central Scotland linking the Atlantic with the North Sea.12 He had long since ruled out the central Panama routes on the erroneous assumption that the mountains there were too high for ditchdigging.13 He also now asserted—incorrectly as he found out toward the end of his life—that the mountain range between the Atrato River and Cupica Bay lowered to such a degree as to disappear. Despite the apparent topographical appeal of the Colombian Darién route, however, Humboldt conceded the primacy of geopolitics: “It appears somewhat probable that the province of Nicaragua will be fixed upon for the great work of the junction of the two Oceans.”14 Nicaragua’s proximity to the United States did later make it very attractive to investors in the north.

Humboldt called for the new Latin American nations to fund engineering surveys of each of the five major routes so as to make an informed decision, and thereby persuade “governments and enlightened citizens” to buy shares in a joint-stock company to finance a transisthmian water communication.15 He warned that the construction process would present unprecedented challenges to the Old World’s hydraulic experts: “The facility of collecting an enormous mass of rain waters within the tropics [for feeding a canal], is beyond what the engineers of Europe can imagine.” Because the tropical forests received at least five times as much rain as Paris, the canal designers would have to take many more variables into account than, say, the landscape architects of Versailles’s famous irrigated gardens.16

Despite his reputation today as a founder of modern environmental thought, Humboldt did not address the issue that would most interest modern environmentalists: the destructive ecological effects of deforesting a large swath of the Continental Divide, removing one hundred million cubic meters of earth, and using the material to form new dams and causeways. That is not to say that deforestation and other transformative human activities did not concern him; on the contrary, he published pioneering critiques of the damaging unintended consequences of clearing tropical lands for plantation agriculture and urban development.17 Yet having worked in the mining industry, Humboldt, like all civil engineers, sought to improve the natural environment for human use and convenience.18

For Euro-American captains of industry, what could be more convenient than a shortcut linking the Pacific and Atlantic realms? An isthmian waterway would revolutionize world trade by precluding the long voyages around Cape Horn and the Cape of Good Hope. Moreover, it would radically alter East Asian relations with western Europe and North America; in Humboldt’s words, “That neck of land against which the equinoxial current breaks, has been for ages the bulwark of the independence of China and Japan.”19 Subsequent events, such as the Anglo-Chinese Opium Wars and U.S. commodore Matthew Perry’s 1853 expedition to Japan, undercut the patronizing idea of East Asian independence as a function of inefficient European access. Nevertheless, framing the Central American waterway as an agent of globalization and Asia-Pacific transformation was prescient.

The only concern Humboldt conveyed in public regarding the canal was the potential for military conflict. He foresaw the possibility that powerful nations might wage war to control the conduit, confessing, “I am not secured from that apprehension either by my confidence in the moderation of monarchical or of republican governments, or by the hope, somewhat shaken, of the progress of knowledge, and the just appreciation of human interests.”20 Indeed, his compadre Simón Bolívar, the revolutionary leader who in 1819 became president of Gran Colombia (a nation encompassing present-day Colombia, Panama, Venezuela, and Ecuador), had rejected an application for a concession to build a canal in 1821 for fear that it “might afford facilities to the enemy” for recolonizing Latin America.21 Such events gave Humboldt reason to doubt that progress and allied Enlightenment values could be sustained far into the future—let alone in the present so as to overcome the epistemic, technological, economic, and political obstacles to solving the canal problem.

Humboldt returned yet again to the interoceanic transit issue in 1849’s Views of Nature. The discovery of gold in California had caused westward traffic to explode around Cape Horn and across Central America, especially in Panama. The difficulty of crossing the Panamanian landmass, though only fifty miles long, by canoe and mule reignited interest in more efficient forms of transportation infrastructure. Yet geographic data remained scarce. Granted, General Bolívar had long since granted Humboldt’s request to commission a survey between Panama City (on the Pacific coast) and the mouth of the Chagres River (on the Caribbean/Atlantic coast).22 It had led to other investigations of central Panama, yet as Humboldt exclaimed, “The most important points on both the eastern and southeastern portions of the isthmus on both coasts have been ignored!” He reprised his call for precise topographical determinations of the entire isthmus, especially the southeastern portion “where it connects to the mainland of South America at the Darién Gap.”23 Yet he omitted the Nicaragua route from the 1849 discussion, a revisionist approach that was telling of the contingency of the canal problem.

In the last decade of his life, Humboldt’s hope for a Darién survey seemed on the verge of fulfillment. In 1854, fearing competition from British and French interests, the U.S. Navy launched the first Darién Exploring Expedition. The party planned to investigate the rumored forty-mile route from the Atlantic Caledonia Bay to the Gulf of San Miguel, an area north of the Cupica Bay route that Humboldt had appeared to endorse in an 1853 letter.24 However, malaria, madness, and starvation cut short the scientific reconnaissance. Popular accounts of the ninety-seven-day ordeal reified perceptions of the Darién as a dangerous wilderness inhabited only by remnants of Indigenous Guna who had survived Spain’s genocidal wars. Tropical diseases and famine had also doomed an infamous 1698 colonization effort that bankrupted Scotland. A century later, even the Spanish retreated from the dense forests and swamplands of the ten-thousand-square-mile mountain pass.25

Before, during, and immediately after the expedition’s mortifying failure, U.S. corporations concentrated on developing new land-based transportation networks to carry California-bound travelers across the isthmus. Central Panama became the site of the first transcontinental railroad in 1855.26 Despite its success, U.S., British, and French teams conducted private and state-supported canal surveys across the nations of Central America during the subsequent decades.27

Seven expeditions received funds from a Wall Street financier, sea-level canal enthusiast, and Darién canal concession holder named Frederick Kelley. Kelley credited the writings of “the illustrious Humboldt” and Admiral Robert FitzRoy, who had captained the famed Beagle voyage of Humboldt’s disciple Charles Darwin, with sparking his interest in the Darién routes.28 In 1856, Humboldt validated Kelley’s quest by receiving him at his home in Berlin and writing him a letter that several outlets reprinted.29 In earlier publications, Humboldt had not said whether the ship channel should be at sea level, but he now came out on Kelley’s side: “The great object to be accomplished is, in my opinion, a canal uniting the two oceans without locks or tunnels.”30 However, Kelley lost his concession and fortune before he could fulfill his hero’s dream. Not until the 1870s did surveyors return to the southeastern Darién sites that had so interested the illustrious naturalist in his final years.31

The Contingent World Wonder

In 1869, a decade after Humboldt’s death and the year that citizens of both North and South America celebrated the centennial of his birth, the French diplomat and entrepreneur Ferdinand de Lesseps oversaw the completion of a technological sensation. The 120-mile-long Suez Canal joined the Mediterranean and Red Seas, cutting 4,300 miles off the voyage between the North Atlantic and northern Indian Ocean. Funded by the sale of shares in the Suez Canal Company, the project took ten years and the lives of thousands of workers, many of them enslaved. Yet the transformation of the desert isthmus into a moneymaking maritime highway cemented France’s reputation for cutting-edge civil engineering, and intensified interest in creating a similar bypass between the Pacific and Atlantic.32

Ulysses S. Grant made the isthmian waterway the subject of his first address to Congress after assuming the U.S. presidency in March 1869, and during his tenure, seven state-sponsored expeditions conducted surveys that built on and refined Humboldt’s routes. For example, as one surveyor, Lieutenant Frederick Collins, tactfully noted, Humboldt was “somewhat misled” as to the actual height of the mountain range near Cupica Bay, the Pacific terminus of one of the Darién sites. Collins argued in 1874 that enough data had been collected to narrow the choice down to three possible routes, none of which included central Panama: “We need consider only Tehuantepec, Nicaragua and the Napipi-Doguado [two river valleys linked by the Atrato], for at one of these three points the canal will surely be built, if built at all.” He then dismissed the Mexican and Nicaraguan options due to “the earthquake question,” making for only one practicable choice, despite the downside of having to tunnel through Colombia’s mountainous terrain.33

Yet despite the historical record of earthquakes in Nicaragua, the route held significant advantages for U.S. interests. It was closer to New Orleans and other U.S. ports than the Panamanian or Colombian sites and easier to excavate than the Tehuantepec route due to the presence of the 103-mile-long Lake Nicaragua and the Caribbean-flowing San Juan River. On the other hand, the lake’s high elevation would require locks to lift and lower ships by as much as 110 feet. Grant appointed a commission to review the conflicting conclusions of the various isthmian expeditions, and in 1876, the three members deemed the Nicaragua route the most advantageous “from engineering, commercial, and economic points of view.”34

But the French beat the Americans to the punch. Shareholders in the Suez Canal Company had experienced handsome returns during its first decade, and buoyed by de Lesseps’s interest in replicating his success in Central America, thousands of French citizens bought shares to build a sea-level canal in the one place Humboldt had firmly rejected: central Panama, roughly parallel to the railroad. Although the mountains there were only a third as high as Humboldt had thought, the heavy rains he had warned of magnified the tendency of the clay-streaked soil to collapse on itself. Even worse than the downpours and landslides were the horrific outbreaks of malaria and yellow fever, which killed twenty-five thousand workers. Carving a channel through rainforests and wetlands did not compare to digging in the Egyptian desert, and by 1889, de Lesseps’s project and career imploded.35

Even as another French company tried to salvage the project by resuming work on a smaller scale from 1894 to 1904, U.S. canal fever remained strong. The 1890 publication of a book by a Naval War College history professor provided a justification for an Atlantic-Pacific link that transcended Humboldt’s focus on commercial exchange. Alfred Thayer Mahan’s tome The Influence of Sea Power upon History, 1660–1783 inspired politicians chastened by the nation’s economic downturn and by perceptions of the frontier’s closure. Rather than accepting that the era of Manifest Destiny was over now that white settlers had filled the lands west of the Mississippi, Mahan argued that Americans must extend their military dominion over the oceans to protect and expand their commercial fortunes, just as Great Britain had become a world power via naval supremacy, maritime trade, and a far-flung colonial network. Mahan called for developing naval bases outside U.S. boundaries. Like islands providing temporary habitat for land birds unable to fly far offshore, such structures would sustain the nation’s fleet of battleships: “To provide resting-places for them, where they can coal and repair, would be one of the first duties of a government proposing to itself the development of the power of the nation at sea.”36

Securing coaling stations throughout the Caribbean Sea would be especially important “if a Panama canal-route ever be completed.” Such a connection would transform the region into a great commercial highway, attracting throngs of European ships and precluding the United States from “stand[ing] aloof from international complications.” Accordingly, no matter who controlled the isthmian canal, U.S. naval ships would need to patrol the Caribbean to defend the southern borders and to project hemispheric authority: “With ingress and egress from the Mississippi sufficiently protected, with such outposts in her hands, and with the communications between them and the home base secured . . . the preponderance of the United States on this field follows, from her geographical position and her power, with mathematical certainty.”37

Mahan’s arguments tapped into a broader pool of interest in modernizing the U.S. Navy and facilitating a paradigm shift toward sea power.38 The benefits of investing in battleships as instruments of economic and foreign policy paid off enormously for the United States in the Spanish-Cuban-American War of 1898, after which Spain ceded Cuba, Puerto Rico, Guam, and the Philippines.39 As Mahan wrote years later, “From a military point of view, these acquisitions have advanced the southern maritime frontier of this country.”40 Defending the new U.S. empire’s tropical frontier, which also included Hawaii, necessitated a Pacific-Caribbean passage more than ever. This was epitomized during the war by the dramatic voyage of the U.S.S. Oregon, which took sixty-six days to rush from San Francisco to the Cuban battlefront by way of Cape Horn; as many observers noted, an isthmian shortcut would have shaved off eight thousand miles.

Several political, economic, and technological forces converged in the half decade from 1898 to 1903 to make the U.S.-controlled Panama Canal a reality. Underlying them all was Theodore Roosevelt’s fervid advocacy. As assistant secretary of the navy during the war, he had helped implement Mahanian goals, and after becoming president in 1901, he lobbied hard for a canal in Panama. Although the House of Representatives had voted for a bill specifying a Nicaraguan route, he and a few key stakeholders seeking to build on the French project convinced the Senate otherwise. Part of their infamous strategy took advantage of a vintage Nicaraguan stamp featuring a spewing volcano, along with the recent news of an eruption elsewhere in the Caribbean, to undermine confidence in the route.41 Congress passed a law authorizing the president to purchase the French syndicate’s assets and rights and to build an isthmian canal, contingent on the negotiation of a treaty with Nicaragua or Colombia, of which Panama had long been a province.

When the Colombian Senate objected to the ensuing U.S.-Colombia treaty on financial grounds, well-connected insiders encouraged dissatisfied Panamanian elites to revolt in 1903. Roosevelt deployed battleships to the Caribbean and Pacific coasts to prevent Colombian troops from suppressing the revolution. No Panamanians took part in the ensuing treaty negotiation, which was led by a French canal agent who benefited from the sale of his company’s assets for $40 million. Phillippe Bunau-Varilla helped craft the 1903 treaty that bore his name and granted the United States extremely favorable terms: the right to build and defend a canal and surrounding zone over which it could rule as “if it were the sovereign” in exchange for a $10 million payment and $250,000 annuity. The inequitable treaty ignited resentment among Panamanians from its inception.42

Having secured, in essence, sovereign rights over the Panama Canal Zone, U.S. officials postponed the decision over whether to continue with de Lesseps’s plans for a sea-level channel. Higher priorities faced the engineers: getting the aged railroad in shape to carry away dredge spoil as fast as the huge steam shovels could dig, and taming deadly tropical disease organisms, an enormous task that drew on twenty years of epidemiological research.43

Roosevelt appointed a board of consulting engineers in 1905 to settle the design issue. He told the thirteen members that he hoped it would be feasible to excavate the entire route at the level of the seas: “Such a canal would undoubtedly be best in the end . . . and I feel that one of the chief advantages of the Panama route is that ultimately a sea-level canal will be a possibility.” However, facilitating interoceanic traffic as soon as possible outranked “the ideal perfectibility of the scheme from an engineer’s standpoint.” A sea-level waterway would shorten transit times, but Roosevelt did not consider it worth adding too many years and safety risks to the construction process. Still, if the board recommended a high-level multilock canal as the most expeditious plan, he desired to know whether it could be converted to sea level at some future point “without interrupting the traffic upon it.”44

The board voted eight to five for the sea-level canal option as the only one “giving reasonable assurance of safe and uninterrupted navigation.” Other lock canals caused “vexatious delays” and accidental collisions, and provided ideal targets for violent adversaries: “The modern lock for ocean-going vessels is a work which an enemy, through stratagem, could with no great difficulty put out of use in an hour or even a few minutes.” By sneaking in dynamite via the surrounding forest or blowing up a transiting ship, saboteurs could disable the canal for months. Moreover, while recognizing that a seaway would cost more and take longer to build, the majority stressed that it would “endure for all time” no matter how large ships might become, and that the construction expenditures (estimated at $250 million and twelve to thirteen years) must be balanced against those of maintaining and defending a vulnerable locked waterway.45

The dissenting board members, however, argued that their colleagues minimized the difficulties posed by the eight-mile-long Culebra mountain portion of the Continental Divide, known as the Culebra Cut. De Lesseps’s crews had managed to lower the summit from 210 feet to 193.5 feet above sea level. Excavating all the way down, even using the latest technology, would take closer to fifteen years—six years longer than a lock waterway with a summit elevation of 85 feet, or as they called it, a summit-level canal. It would also cost $100 million more, “not a trifling sum, even for the resources of the United States.”46

The minority report engineers also rejected the majority’s assessment of the disproportionate risks posed by lock canals. Even a sea-level canal, they argued, would be vulnerable to attack at its tidal-regulating structure, a device needed to account for the different maximum tidal ranges on either side of the isthmus. As surveyors had quantified several decades previously, the Pacific tides rise and fall twenty feet each day, whereas the Caribbean tides move only two feet. In a sea-level channel, depending on the time of day, the resulting current flows might compromise navigational safety. A tidal-regulating structure at the Pacific terminus would enable engineers to adjust the currents at a given moment to the desired velocity—but of course not if saboteurs took them out.47

As for the question of accommodating likely increases in ship size, the pro-lock group questioned the wisdom of trying “to meet the possible requirements of a distant future, which might be estimated erroneously and would burden the commerce of the present and near future with unfavorable conditions.”48 Larger locks could be built if and when needed. Though Roosevelt’s question about the mechanics of conversion remained unanswered, he could not have agreed more with the board’s minority members.49 Construction on the summit-level canal proceeded in 1906, and within a few years, the idea that there had been an alternative receded from public memory: “The controversy that once raged so furiously now seems to have been but a tiny tempest in an insignificant teapot.”50

Girdling Panama

The megaproject imposed immense changes on the Panamanian landscape. To control the insect-borne diseases that had killed so many of de Lesseps’s workers, sanitarians drained wide swaths of wetlands, installed drinking-water systems in the port cities of Colón and Panamá, and sprayed hundreds of thousands of gallons of oil and larvicide.51 To carve out the canal bed, workers excavated over 150 million cubic meters of rock and soil—enough to create both the two-mile-long Amador Causeway guarding the waterway’s Pacific entrance and the world’s largest earthen dam. Closer to the Atlantic side, the 1.5-mile-long Gatun Dam channeled the Chagres River into the world’s largest reservoir, Gatun Lake, to serve as the canal’s water and electricity source. To move so much soil, crews from Barbados, Jamaica, and many other nations mobilized massive steam shovels and hydraulic rock crushers shipped from the booming factories of the Ohio River Valley and Great Lakes. They also installed three pairs of Pittsburgh-forged locks—each measuring 110 feet wide by 1,000 feet long—to lift ships 85 feet above sea level. The ingenious “bridge of water” used fifty-two million gallons of fresh water from the Chagres for every transit.52

U.S. officials also disrupted the region’s human communities by depopulating towns to make way for the ten-mile-wide Panama Canal Zone, an enclave designed to house the waterway’s civilian employees and military defenders (map 1.3). The radical reshaping of central Panama’s human-dominated landscape was not an unavoidable byproduct of canal construction. Rather, it resulted from specific decisions that benefited the United States—choices that were easy to forget as second-growth forests took root in cleared fields, and as the waters of Gatun Lake submerged what had been for over three centuries an intensively cultivated valley.53

Creating the massive bridge of water and its buffer zone required technological, scientific, and organizational expertise, which countless magazine spreads, postcards, popular books, and world’s fair exhibits commemorated with jingoistic flair.54 “Every American can take a just pride in this girdle which we have flung across the isthmus,” enthused one author, especially since “we are the nation which . . . Providence . . . has decreed should build the canal . . . to confer a lasting benefit on the world at large and usher in a new age of culture.”55 Americans also took pride in photographs depicting Roosevelt, who defended his actions against Colombia, visiting the construction site. The image of him operating a steam shovel in a white linen suit became a powerful icon of the conquest of nature and other nations. Grade school U.S. history textbooks replicated such heroic representations throughout the twentieth century, reinforcing belief in the project’s inexorableness and righteousness among generations of U.S. citizens.56

Publicity regarding the Panama Canal played up its international commercial benefits and the munificent U.S. policy of keeping tolls low rather than trying to recoup the $400 million cost. Of course, as later analyses revealed, low tolls functioned as a subsidy for U.S. shippers moving goods from coast to coast.57 The elderly Mahan, not surprisingly, stressed the incalculable national security benefit of moving the U.S. naval battalion between oceans as needed. While the fleet would have to be maintained in the Atlantic for the foreseeable future due to the West Coast’s inferior coal deposits and high labor costs, ships could steam from Norfolk, Virginia, to Pearl Harbor, Hawaii, in four weeks rather than four months.58

Perhaps less expectedly, the retired naval historian-officer also promoted the waterway as a bastion against what Roosevelt and other nativist contemporaries called “race suicide.”59 Viewing the West Coast as underpopulated and in need of more white immigrants, Mahan declared, “The great effect of the Panama Canal will be the indefinite strengthening of Anglo-Saxon institutions upon the northeast shores of the Pacific, from Alaska to Mexico, by increase of inhabitants and consequent increases of shipping and commerce.” Passenger ships transiting the new canal would enable white Europeans and East Coast residents to make the journey at a lower cost than the transcontinental railroad or Great Lakes steamers.60

Conclusion

How would Humboldt have responded to such martial and white supremacist rationales for the transisthmian canal? Probably not favorably. He had expressed explicit concern about nations fighting to control such a conduit, and more broadly, he rejected scientific racism and its allied institution, slavery. “Whilst we maintain the unity of the human species,” he wrote in the blockbuster first volume of Cosmos in 1845, “we at the same time repel the depressing assumption of superior and inferior races of men.”61 Moreover, his critiques of Spanish colonial policies that degraded human and ecological communities had bolstered the Latin American independence movement led by Simón Bolívar.

At the same time, Humboldt’s canal advocacy must be seen in the context of his contested role as an agent of imperialism.62 Speculation that he shared his canal intelligence prior to publication with U.S. president Thomas Jefferson supports the view of him as a proponent of using scientific knowledge and tools to promote Euro-American dominance and Northern Manifest Destiny.63 Due to the problematic imperial as well as environmental dimensions of the canal enterprise, more historiographical attention to his private and public writings on the subject might help address the question of whether Humboldt deserves his reputation as the founder of modern environmental thought.64

For the purposes of this book, Humboldt’s English language publications in favor of the canal illustrate the historical contingencies of megaproject planning. Despite being the world’s most famous scientist—one who succeeded in getting other projects off the ground (such as networks of magnetic and meteorological observatories)—he failed for forty years to convince officials to conduct comprehensive surveys of all the routes he had identified. Conducting the scientific reconnaissance work, let alone the large-scale engineering of the actual structure, required favorable political, economic, and technoscientific forces to coalesce at the right moments.

Humboldt’s advocacy also challenges notions of geographical and historical determinism that permeate popular writings on the Panama Canal.65 A determinist perspective emphasizes notions of inevitability and predestination. Consider this quote, crafted the year after the maritime highway opened for business: “The valley of the Chagres was framed by the hand of Nature in such a way as to fit admirably into the plans of the canal engineers for a lock canal across the isthmus, with the Atlantic locks at Gatun.”66 Of course, for Humboldt and other nineteenth-century canal enthusiasts, it was not obvious that a lock design would prevail nor that the Chagres River valley in central Panama offered the ideal site. As a U.S. senator wrote in 1837 of the southern Atrato River valley, “Nature seems to have designed this for the passage. The Andes are here for a moment lost, and in obedience to the will of Providence and the wants of man, seem to have defiled [narrowed], that commerce may march from the old world to the new.”67

By the time of the Panama Canal’s completion, people had already begun to forget the alternatives that had been the subject of intense debate for decades. Popular authors depicted de Lesseps’s failure as a foil to the U.S. initiative, conceding that the French provided “the knowledge that made it possible for us to avoid their mistakes and profit by their experience.”68 Knowledge of the tangible and intangible things needed for a sea-level canal was indeed valuable and worth remembering, as events would prove sooner than expected.