Map of US and British North America, 1807.

“Up to our own day, American history has been in a large degree the history of the colonization of the Great West.” -Frederick Jackson Turner, 1893

“Like many historians, Turner was interpreting the past in light of recent events. This presentism had great benefits and also great risks. History was bound to to go on. . . Turner himself moved on. In his later essays, he kept adding ‘more history’ as it accumulated. . .” -Patricia Nelson Limerick, 1987

On February 19, 1807, Vice President Aaron Burr was captured after escaping his earlier arrest when President Jefferson accused him of treason for his role in a conspiracy to colonize parts of Mexico. Seven days later, on February 26, Lieutenant Zebulon Pike and the members of his expedition into the Southwest (which Jefferson ordered) were captured by Spanish authorities and taken to Chihuahua, then under Spanish control. He used the opportunity to analyze New Spain’s weaknesses for the possibility that the US would try to colonize parts of Mexico. The American Frontier, as Turner insists in his “Frontier Thesis,” shaped American historiography, but in 1807, what became the frontier was a highly militarized border zone.

The Pike Expedition began the year Lewis and Clark returned from their own expedition to the Northwest. Exploring modern-day Colorado, Pike lost members to abandonment or bad weather while wandering across the porous border into Mexico.

In his journals, Pike kept careful account of what he encountered, gathering information about local governments and geography. On their way to Chihuahua, Pike notes on March 27 that he “saw the Gazettes of Mexico, which gave rumors of colonel Burr’s conspiracies, the movement of our troops. . . stated in so vague and undefined a manner, as only to create our anxiety without throwing any light on the subject” (Pike, Journals, 240). He later notes on April 24 that he was reprimanded for discussing “subjects of religion or politics” but that he was held as a guest “under coercion of the Spanish government” and not as a prisoner of war. Pike then writes that he patriotically declared to Spanish authorities (over dinner with them): “To my government I am certainly responsible, and to no other” (246).

Because he was so dedicated to his government, Pike ended his 1810 account of his expedition by offering one final conclusion about US-Mexico relations:

“Should an army of Americans ever march into the country, and be guided and governed there by these maxims, they will only have to march from province to province in triumph, and be hailed by the united voices of grateful millions as their deliverers and saviors” (Pike, Expedition, 806). As Vice President Dick Cheney put it two centuries later, “we will, in fact, be greeted as liberators.” This is how the US framed the frontier at the beginning of the nineteenth century: as a foreign nation in need of democracy and order.

Spanish colonial officers were suspicious of Pike’s discussions of politics with the locals because they feared that the US, which had separated from the English crown, would inspire Mexico to separate from the Spanish crown, as independence became increasingly popular in the region. Coupled with vague rumors that rogue US politicians planned to conquer sections of North America for themselves, the Spanish authorities had good reason to be suspicious. In 1810, independence movements spiraled into nationalist protests and a bloody war, forcing Spain to grant Mexican independence in 1821. Years later, the US would follow Pike’s advice and invade Texas and northern Mexico in the Mexican-American War of 1846. Unlike Pike predicted, though, the US military was not greeted as liberators.

Meanwhile, Aaron Burr and his compatriots were punished for trying to instigate exactly what Pike recommended. Jefferson’s exertion of control over who could, and who could not, conquer parts of New Spain demonstrates his role in creating the concept of the “American frontier” as a strategic borderland, rather than a raw, untamed wilderness.

New Western historian Patricia Nelson Limerick notes that the “opening of the Mexican borderlands to American colonists and merchants made the region into what it remains today: a true frontier, in the European sense, in which two nations confront each other and compete for control” (228). She goes on to detail Burr’s plot, alongside General James Wilkinson, to colonize parts of the continent and create a new nation using the available resources, admitting that when “Zebulon Pike set out to explore the headwaters of the Arkansas River in 1806, he might have been acting as Wilkinson’s agent” (229).

Intelligence about the borders of New Spain, then, became part of the ideological basis for the American frontier. The distance between Arkansas and Chihuahua was labeled the frontier because it was a borderland rather than a boundary, like the no-man’s land between trenches on the Western Front in World War One. Turner’s “Frontier Thesis” says more about how Americans viewed themselves in the 1890s than in the 1810s. The frontier was framed as contested territory. By the time Turner delivered his thesis, there was no longer a contest in federal or popular imagination.

But the frontier was also about quantification. First, the US had to map, measure, and count everything available in the frontier space, to determine where the gold, silver, copper, fur, timber, coal, and indigenous communities could be found, and where they could be removed to. Knowledge of the land preceded the frontier, rather than the other way around. This is the way American contradiction manifests in the frontier thesis: Americans wanted to discover land that had already been discovered, to be given access to the land they were told to imagine. A blank map could not be tolerated. It had to be filled out.

Limerick, Patricia Nelson. Legacy of Conquest. W. W. Norton & Company, 1987.

Pike, Zebulon. The Expeditions of Zebulon Montgomery Pike. Harper, 1895.

Pike, Zebulon. The Southwestern Journals of Zebulon Pike, Ed. Stephen Hart & Archer Hulbert. University of New Mexico Press, 2006.

Turner, Frederick Jackson. “The Significance of the Frontier in American History.” In The Early Writings of Frederick Jackson Turner, Ed. Everett E. Edwards, University of Wisconsin Press, 1938.