From Sea to Sea: The Northwest Passage, Early America, and the Push to the Pacific Ocean

Sean Fraga

Title page of Daniel Coxe’s A Description of the English Province of Carolana, 1741. Courtesy of Hathi Trust.

Everyone in colonial America knew the Northwest Passage was out there. Hidden somewhere among western North America’s towering mountains and sweeping plains was a water route that would link the Atlantic world with the Pacific Ocean, opening a faster, more lucrative route for trade with China. But the details were hazy. Was the Northwest Passage an arm of the sea? Was it formed by two rivers with common headwaters? Could deep-water ships sail straight between the oceans, or would only smaller craft, like canoes and bateaux, be able to traverse the passage? Would there be portages? Waterfalls? Ice? Every failure to find the Northwest Passage—and there were many failures—served only as further proof that the passage itself remained undiscovered.

Northwest Passage dreams shaped American expansion projects across the long nineteenth century, influencing everyone from eastern merchants to western settlers to the builders of the transcontinental railroads. I study U.S. colonization of the North American West and engagement with the Pacific Ocean. In my book project, a critical cultural and environmental history of Puget Sound harbors, I argue that Americans spent decades remodeling Puget Sound around transpacific trade. But to understand why this was an appealing goal—indeed, to understand why Americans fixated on Puget Sound at all—we need to start on the other side of the continent, in colonial America and the Atlantic world.

First as British colonists and then as postcolonial nationalists, Americans imbibed European geographic theories and carried Europeans’ long pursuit of a Northwest Passage into the North America West. Thomas Jeffersons life and work captures this trajectory in microcosm. Jefferson learned about the Northwest Passage as a child in colonial Virginia and his lifelong fascination with it culminated in his organization of the Corps of Discovery (1803–1806) to search for a water route between the oceans. Jefferson believed Americans could use the North American West to reach the Pacific Ocean. His beliefs are significant both for how perfectly they represent a particular school of late-eighteenth-century geographic thought, and for their enduring influence on American understandings of the North American West across the nineteenth century.

The search for new trade routes with Asia had long defined European engagement with the terraqueous globe. In 1492, Christopher Columbus sailed west across the Atlantic, hoping to bypass Portuguese-controlled routesto Asia for his Spanish patrons. As Europeans colonized the Americas, dozens of expeditions probed the Atlantic coast, encountering rivers, bays, even a sprawling freshwater inland sea—the Great Lakes—but no interoceanic passage. These expeditions’ published narratives and maps circulated widely within the Atlantic world and fed European beliefs about the inevitability of a Northwest Passage.

Thomas Jefferson first heard of the Northwest Passage as a child, when his father’s associates talked in 1749 of following the Mississippi and Missouri rivers to the Pacific Ocean. After all, they reasoned, Virginia’s 1609 charter granted the colony territory “from sea to sea,” and Daniel Coxe’s influential geography of North America (published 1722, republished 1741), promised “an easy communication betwixt the River Meschacebe[Mississippi], and the South Sea [Pacific Ocean], which separates America from China” (emphasis original). The Seven Years’ War prevented this expedition, but the possibility of a Northwest Passage was taken seriously by educated British colonists in North America. (Around the same time, for example, Benjamin Franklin organized two Northwest Passage expeditions out of Philadelphia.)

As a schoolboy, Jefferson learned the British theory of symmetrical geography, which held that North America’s two halves were mirror images of each other. This meant the Missouri River would have a western counterpart—perhaps with common headwaters, perhaps separated by a short portage. Symmetrical geography both explained territory as yet unexplored by British colonists, and (like Coxe’s geography) suggested a North American route to Asia. The idea stuck with Jefferson: Years later, he mused in his first and only book, Notes on the State of Virginia (published 1784), about the possibility of portaging between the Missouri and the Rio Grande.

“A map of Lewis and Clark’s track across the western portion of North America, from the Mississippi to the Pacific Ocean,” 1814. Courtesy of the Library of Congress.

Jefferson wrote Notes in the wake of the American Revolution and used it to tell a new national story. But he also rooted Virginia’s history within British explorations for a Northwest Passage, closing the book with a chronological bibliography. The very first item on this list is letters patent authorizing John Cabot to search the North Atlantic for a peninsular Horn of Asia, issued by King Henry VII in 1496 amid European excitement following Columbus’s first voyage, and documents from numerous other Northwest Passage explorations punctuate the list. Jefferson’s bibliography shows how British ambitions for Asian trade intertwined with British colonization of North America and hints at how Americans inherited this vision.

While U.S. Minister to France, Jefferson searched European bookstores for texts on North America. He bought British books on symmetrical geography, including Coxe’s. He bought French books on pyramidal height-of-land theory, which posited that several North American rivers flowed in different directions from common headwaters. He bought Spanish books predicting a connection between the Strait of Anián and the Great River of the West. As Jefferson read in English, Spanish, and French, he found different ideas pointing toward the same conclusion: There was a water route across North America.

In the late eighteenth century, Europeans extended their search for the Northwest Passage to the Pacific Ocean. British Captain James Cook’s 1776–80 Northwest Coast reconnaissance failed to find the passage, but opened a new trade in marine mammal furs between Euro–American merchants, Northwest coast Native peoples, and Chinese buyers. At the same time, American trade with China had grown in economic importance since the Revolution, amplifying the potential value of a Northwest Passage. More than ever, Jefferson worried a European power might occupy the Pacific coast.

After repeated attempts to send American explorers overland to the Pacific, Jefferson’s pursuit of the Northwest Passage reached its climax with the Corps of Discovery. Jefferson’s instructions to Meriwether Lewis and William Clark were clear: Find “the most direct & practicable water communication across this continent for the purposes of commerce.” Jefferson believed the Missouri River would link with a western river flowing to the Pacific Ocean. Despite his years of study and voluminous library, Jefferson’s geographic beliefs remained strikingly similar to those of his fathers associates more than fifty years earlier.

But on reaching the Missouri’s headwaters, Lewis and Clark found “tremendious [sic] mountains . . . covered with eternal snows” between them and the Pacific. For trade with Asia, Lewis wrote, the overland route “will never be found equal” to existing sailing routes around Cape Horn. In this regard, the expedition was a failure.

Or was it? Americans soon decided that if the Northwest Passage did not exist, they would simply have to build it. Jefferson, like the European geographers he read, imagined rivers as natural interoceanic corridors. But a new generation of Americans, enthralled by steam power and emboldened by ideas of Manifest Destiny, envisioned a mechanical portage between the oceans—the transcontinental railroad. By the 1840s, Puget Sound and other Pacific coast harbors became newly valuable as potential exchange points for ships and trains. Over the balance of the nineteenth century, an enduring American obsession with Asian trade combined with new technologies to drive U.S. expansion into the North American West and bring the Pacific Ocean closer to the Atlantic world than ever before.

6 June 2022

About the Author

Sean Fraga is Mellon Postdoctoral Fellow at the University of Southern California.

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