The Myth of America’s Westward Expansion

Robert E. May

Lately, considerable controversy has swirled over how U.S. history education marginalizes the story of Hispanics/Latinos in the geographical space that became the United States of America, a deficiency inadequately redressed by annual observances (since 1989) of National Hispanic Heritage Month between September 15 and October 15. 

According to many authorities, U.S. social studies and history students encounter what M. Elizabeth Boone dubs an “English-only definition of U.S. national identity.” Boone observes that between 1876 and 1915 the United States constructed its history by originating the nation at Plymouth Rock rather than in places with Spanish exploration and colonization histories—e.g., Florida and New Mexico–setting the nation on the path reflected in modern education. This in a country whose Hispanic/Latino population surpasses 18 percent and that has more speakers of Spanish than Spain, and where more than one in four public school students is of Hispanic/Latino background.[1] When author Carrie Gibson subtitled her recent book El Norte about persons of Hispanic/Latino descent in North America as an “Epic and Forgotten Story,” she chose her second adjective advisedly.[2]

Recently, Texas Twentieth District Congressman Joaquin Castro complained to an interviewer, “we have been left out of much of the telling of American history and our state histories, including in my home state of Texas.” Not only do such omissions damage the self-esteem of Hispanics/Latinos, they also, Castro argued, make them historically invisible to the nation’s population writ large, since Americans typically fail to “associate us with any particular time period” in their country’s past. Castro quipped that the only Latino or Mexican American persons he encountered during his social studies education in San Antonio were confined to defending the Alamo during the Texas Revolution.[3]

Although causatively linking such erasures to chronically high national dropout rates for Hispanic/Latino students from U.S. public schools is problematic given the multiple factors contributing to dropout decision-making,[4] they likely are a contributing factor. U.S. social studies coursework highlighting mythologies of American prosperity, innocence and exceptionalism strikes many Hispanic/Latino students as irrelevant to their own worldviews, self-identities, and prior life experiences (especially including high poverty rates in Hispanic/Latino communities).[5] To be sure, content omissions and distortions are being contested at state, regional, and national levels.[6] But remedial initiatives as are now underway in Connecticut are offset by countervailing pressures, especially as blowback against the teaching of critical race theory subverts the logic of Hispanic/Latino studies.[7]

What explains this marginalization? Should we casually chalk it up to the racism, ethnocentrism, and subconscious prejudices of Anglo historians, schoolteachers, and textbook publishers? Or is something else also at work?

As a historian whose books have centered on the efforts of white southerners to expand their slave labor system (the so-called “peculiar institution”) southward into Latin America before the Civil War, I suspect that conventional assumptions that America expanded westward degrade Hispanos/Latinos in U.S. social studies/history education in subtle but profound ways by predetermining the very framing of the nation’s historical narrative.

Let me suggest that by simply reimagining the very geography and maps of U.S. nineteenth-century territorial expansion we might make history education more relevant to Hispanic secondary and even collegiate students. I do not offer this corrective naively as a cure-all for disconnects between Hispanic/Latino students and U.S. history. But I do think it provides one way to jump-start the remedial process.

The problem derives at least in part from a 129-year-old theory. On July 12, 1893, the University of Wisconsin history professor Frederick Jackson Turner, at the World’s Columbian Exposition in Chicago, gave arguably the most influential speech by an American historian in U.S. history. Turner wrote the address, entitled “The Significance of the Frontier in American History,” as a reaction to a recent announcement by the superintendent of the U.S. 1890 census that the country was now so settled it no longer had a clear frontier line. 

In his speech, Turner attributed his nation’s evolution and culture to its waves of movement westward and the norms fostered by its frontier process during each wave. As he put it in one of his first sentences, “The existence of an area of free land, its continuous recession, and the advance of American settlement westward, explain American development.” In what followed, Turner elaborated his “frontier thesis,” explaining that the experiences of living primitively on successive frontiers encouraged the emergence of America’s distinctively national traits—particularly egalitarianism, representative democracy, inventiveness, and nationalism.[8]

Over the following century, academic historians refuted particular arguments within Turner’s frontier thesis. For instance, they contended that it can just as easily be argued that American democratic institutions arose first in heavily populated eastern areas as on the frontier.[9]

But historians rarely challenged Turner’s core insinuation that U.S. territorial expansion occurred in an exclusively westward direction. Turner’s biographer Ray Allen Billington helped ensure this longevity with his lengthy 1949 tome Westward Expansion: A History of the American Frontier, a standard textbook mildly corrective of Turner’s theories that was assigned in many collegiate western history courses and went through six editions. On his book’s third page, Billington called on readers to picture “the Anglo-American frontier as a migrating geographical area which moved westward from Atlantic to Pacific over the course of three centuries.”[10]

This entwining of western migration and American expansion is so embedded in the nation’s historical narrative that historians reaffirm the trope reflexively. Books about U.S. history abound in pronouncements and asides that American expansion pointed westward. In his Pulitzer Prize winning study What Hath God Wrought: The Transformation of America, 1815-1848, Daniel Walker Howe notes that “westward expansion rendered inescapable the issue [slavery] that would tear the country asunder a dozen years later.” In Sex and Manifest Destiny: The Urge That Drove Americans Westward, Martin Naparsteck asserts an intention to illuminate how “the natural human sex drive contributed to the drive to expand the United States westward across the entire continent.” A historian of America’s secession crisis observes how “slavery’s expansion into the West was the chief point of contention between North and South in the 1850s.” A student of American foreign policy suggests it is high time that scholars place the history of “U.S. westward expansion” within the context of European colonialism.[11]

Similarly Turnerian have been the many books for young readers titled Westward Expansion, aimed at students in elementary and secondary education. 

No wonder that with historians preaching America moved relentlessly westward, the association repeats ad nauseum in incalculable numbers of forums. St. Louis’s Museum at the Gateway Arch promotes itself as an institution covering “201 years of history about the westward expansion of the United States.”[12] C-SPAN online programs offer titles such as “American Westward Expansion” and “Civil War and 19th Century Westward Expansion.”  

The thing is, America’s pre-Civil War territorial expansion was not nearly as uni-directional as the stereotype maintains. Though there are no C-SPAN videos titled “American Southward Expansion,” much of U.S. territorial expansion before the Civil War occurred southerly as well as westerly, as people realized at the time. During one congressional debate two years before the Civil War, Senator John Hale of New Hampshire, a onetime minor party presidential candidate, griped, revealingly, that America’s expansion “always travelled South” (rather than northward or westward)![13]

Despite American leaders’ ambitions during the War of 1812 and at other times in the nineteenth century to annex the Canadian provinces, then British colonial possessions, to the U.S. domain, those dreams were never realized (though Anglo-American boundary adjustments in the 1840s could be interpreted as adding small slices of Canada).[14] In contrast, the U.S. made huge gains to the south before the American Civil War at the expense of France, Spain, and Mexico by the Louisiana Purchase from France (1803), the Transcontinental (or Adams-Onís) Treaty with Spain (1819) acquiring Florida, the annexation of Texas (1845), the Mexican Cession ending the U.S.-Mexican War of 1846-1848, and the Gadsden Purchase from Mexico (signed in 1853 and ratified in 1854). The latter gained nearly 30,000 square miles of Mexico that eventually was incorporated into the southern reaches of today’s states of New Mexico and Arizona.

To be sure, these acquisitions grew America westward. This holds even for Florida. Its “panhandle” lies west of coastal states like South Carolina and Georgia. Further, the Adams-Onís Florida treaty defined a U.S.-Spanish boundary in the southwest along the 42nd parallel extending to the Pacific Ocean, eliminating a potential Spanish impediment to future U.S. designs on the Pacific Northwest. Today’s southern and onetime slave state of Louisiana was only a fraction of the territory France gave up in 1803 for $15 million in 1803, as the Louisiana Purchase cession included some 828,000 square miles from the Mississippi River to the Rocky Mountains.[15]

Yet, too often overlooked is that all these acquisitions pointed southward as much as westward, as even a most superficial glance at a map of the continental U.S. shows. 

Louisiana might have been west of Georgia and Florida, but it was south of Wisconsin and Minnesota and southwest of states like Massachusetts, Pennsylvania, and New York. More to the point, slavery was legal in the entire Louisiana Purchase territory when Thomas Jefferson’s administration negotiated its acquisition from France, and its lower and most heavily populated extremes, including the current state of Louisiana, had an established staple crop economy and a population about 50% enslaved.[16]

For all of his well-known, stated reservations about the evil effects human bondage had alike on slaveholders and the enslaved, Jefferson initiated no steps to eradicate the institution in his new acquisition either before or following the treaty’s drafting or ratification.[17] Indeed, Article 3 of the purchase treaty ensured that current residents would hold the same “rights, advantages and immunities” of U.S. citizens after annexation including their “property” (emphasis mine), granting Louisiana’s pre-annexation slaveholders legitimate title to their slave property equivalent to  that already held by U.S. slaveholders.[18]

We must not forget that the U.S. southern slave states of Louisiana, Missouri, and Arkansas never would have come into being had it not been for the Louisiana Purchase, and it is likely the U.S. never would have gained the slave state of Texas had it not first acquired adjacent Louisiana to its east. An immediate boom in Louisiana slave-produced sugar followed the U.S. takeover. And yet, somehow, we tend to remember the Louisiana Purchase as part of America’s unceasing march westward rather than westward and southward.

And what about Texas, also south or southwest of much of the remainder of the United States at the time? As Annette Gordon-Reed (on the basis of her own experiences attending Texas schools) reminds us in On Juneteenth, the state’s nineteenth and twentieth century history is commonly stereotyped as a western tale of cowboys, ranchers, and oilmen. This is horribly misleading, eliding Texas as a southern chapter of U.S. territorial growth. It obscures the “extremely humid subtropical climate” of eastern Texas, where cotton culture and slave labor flourished in the wake of American infiltration in the 1830s and annexation in 1845. Gordon-Reed pointedly notes that the legendary William Barret Travis, who commanded the revolutionary forces at the Alamo in 1836, brought an enslaved servant there. So did his famed fellow revolutionary Jim Bowie, who previously had been involved in slave-trading and brought his enslaved cook Betty with him to the besieged onetime mission.[19]

Had Texas lacked potential for slave-produced cotton, few settlers from slave states would have migrated there in the 1830s, and it is possible the United States never would have annexed it in 1845. Without an economy revolving around slave-produced cotton at the time of Lincoln’s election, it is unlikely Texans would have voted in 1861 to secede and join the Confederacy. Arguably, Texas remains today more a southern state than a western one. But it was certainly so in the mid-nineteenth century.

As Rachel St. John–an expert on the geography of U.S. expansion–notes, we would be better served conceptualizing Texan annexation within “a distinctly southern and pro-slavery view of American destiny” than as part of America’s rush to the Pacific.[20] At the very least, the story of Texas annexation and statehood is as much a tale of America’s southward expansion as evidence of its westward thrust.

And although the Mexican Cession and Gadsden Purchase allowed U.S. settlement and development of the Southwest and California and facilitated American commercial and eventual territorial penetration of the Pacific and Asia (e.g., Hawaii and the Philippines), it is incomplete to state, as one historian does, that the acquisition of Mexican territory in the 1830s and 1840s “ignited violent new battles over whether slavery would be allowed to expand west.” These very acquisitions paved the way for potential U.S. expansion projects in Latin America.[21]

It was in the 1850s that U.S. adventurers known as “filibusters” followed up on their nation’s prior expansion by invading and trying to conquer Mexico and Central America as well as Spain’s then colony in Cuba.[22] One filibuster, William Walker, conquered most of Nicaragua and legalized slavery there, though it had been previously abolished in Mexico and all of Central America.[23] During the 1850s, both U.S. presidents, Franklin Pierce and James Buchanan, tried to buy Cuba from Spain. In 1854, America’s most important diplomats in Europe convened in conference in Belgium and issued their infamous “Ostend Manifesto” arguing that if Spain refused to sell Cuba to the U.S., that the U.S. would have justification to seize it and keep it.[24] And in the years immediately before the Civil War, U.S. President James Buchanan seriously pursued the project of gaining his country a protectorate over Mexico. 

Few students in U.S. schools learn that a disagreement over whether U.S. slavery should be allowed to expand into Latin America played a significant role in the famed rivalry between Abraham Lincoln and Stephen Douglas. Nor are they informed that disagreements over this same issue helped shatter all hopes following Abraham Lincoln’s election in 1860 that the North and South might resolve their differences over slavery with a compromise, warding off the civil war that followed. They might learn that before the Civil War there were movements to “colonize” U.S. slaves and free Blacks in Africa, but probably never get an inkling of the efforts to colonize U.S. Blacks in Latin America, especially during the Civil War.[25]

I am suggesting here the need for educators, state departments of instruction, and textbook companies to collaborate in designing a corrective history/social studies curriculum that, shorn of Turnerian perspectives, reframes the American story by highlighting that America became a continental empire by extending south as well as west. Such a curriculum would have to do more than cover Spanish conquests and settlement of Florida and the Southwest during America’s colonial period (a feature common to many U.S. social studies and history textbooks at all educational levels), the Texas Revolution, and the U.S.-Mexican War. Rather, this reframing would need to be chronologically expansive, thoroughly infusing treatments of U.S. history from the American Revolution onward.

Let me give just one example of how this kind of a revamped social studies curriculum might better engage Hispanic/Latino students. When studying the filibuster invasion of Mexico in 1855 by Texas Ranger officer James Hughes Callahan, an attack that burned and plundered the border town of Piedras Negras, Mexico, I became aware that a key incentive for the invasion was the desire of Callahan and his men to recover slaves who had escaped bondage in Texas by fleeing across the Rio Grande.[26]

White southerners before the Civil War, in fact, were infuriated at Mexico for providing haven to their enslaved people.[27] Students need to learn about this twist on our usual narratives about the Underground Railroad. Nearly always, we picture British Canada as the safe refuge for escaped enslaved Blacks hoping to get beyond the grasp of Congress’s Fugitive Slave Act of 1850. Yet, several thousand slaves sought freedom in Mexico.[28]

Highlighting the Mexican alternative for escaped slaves, in turn, invites classroom investigations into Mexico’s antislavery history, the roots of cultural differences between the U.S. and its neighbor to the south, and, for that matter, the history of slavery and abolition in Central American states as well. Students might instinctively wander from such material into the racial, ethnic, and gender constraints on the U.S.’s heralded democratic traditions and history.[29]

This is the very kind of inquiry, incidentally, that Critical Race Theory in its best applications invites. It is, after all, a testament to Mexico’s less rigid race conventions that many escaped slaves sought Mexican citizenship after arriving there. Such musings might be a seamless lead-in to classroom considerations of the significance of the U.S. Supreme Court’s definitions of citizenship in the Dred Scott Decision of 1857, a case that all high school graduates should understand. 

In an assessment of the impact of the standards movement in U.S. social studies education on Latino students, Kennesaw State University Assistant Professor of History and History Education Caroline Conner recently suggested that although the Obama administration’s Every Student Succeeds Act (2015) has arguably improved the coverage of African American and Native American history within U.S. secondary education, at least superficially, it has been less constructive when it comes to Latinx and Asian American inclusion. Instead, those groups continue to be “drastically underrepresented and misrepresented.”[30] Potentially, a re-directing of the common wisdom about U.S. territorial expansion might help social studies/history recapture forfeited Hispano/Latino audiences. We need to conquer our simplistic presumption that America expanded westward. Otherwise, that very trope will continue to stifle the thirst for history learning among U.S. minority populations.


Robert E. May, Professor Emeritus of History at Purdue University, is the author of three books dealing with U.S. western and southern territorial expansion: Slavery, Race, and Conquest in the Tropics: Lincoln, Douglas, and the Future of Latin America (2013) Manifest Destiny’s Underworld: Filibustering in Antebellum America ( 2002); The Southern Dream of a Caribbean Empire, 1854-1861 (1973, 2002). Among his other publications is his essay in the December 1991 issue of the Journal of American History, “Young American Males and Filibustering in the Age of Manifest Destiny: The United States Army as a Cultural Mirror.”


[1]M. Elizabeth Boone, “The Spanish Element in Our Nationality”: Spain and America at the World’s Fairs and Centennial Celebrations, 1876-1915 (2019), 1, 2, 11 (quotation on 1); “Education,” “Unidos US,” Oct. 6, 2021,

[2]Carrie Gibson, El Norte: The Epic and Forgotten Story of Hispanic North America (2019).

[3]Joaquin Castro interview in Stephania Taladrid, “The Exclusion of Latinos from American Media and History Books,” New Yorker, Sept. 21, 2021. 

[4]Caroline J. Conner, “Whitewashing U.S. History: The Marginalization of Latinxs in the Georgia Standards of Excellence,” Journal of Latinos and Education, July 22, 2021. 

[5]Paul Ortiz, An African American and Latinx History of the United States (2018), x, 5, 6; James W. Loewen, Lies My Teacher Told Me: Everything Your American History Textbook Got Wrong (2008), 1, 70, 343-344.

[6]Christopher Peak, “Latina Student: What About Our History,” New Haven Independent, Nov. 13, 2019

[7]“Extend Black and Latino History Curriculum Throughout K-12 Education in Connecticut: That May Be Next Step,” Connecticut by the Numbers; Conner, “Whitewashing U.S. History.”

[8]Frederick Jackson Turner, “The Significance of the Frontier in American History.”

[9]Allan G. Bogue, “Frederick Jackson Turner Reconsidered,” The History Teacher, 27 (Feb. 1994), 195-221.

[10]Martin Ridge, “Ray Allen Billington, Western History, and American Exceptionalism,” Pacific Historical Review, 56 (Nov. 1987), 503; Ray Allen Billington, Westward Expansion: A History of the American Frontier (1967), 3.

[11]Daniel Walker Howe, What Hath God Wrought: The Transformation of America, 1815-1848 (2007), 852; Martin Naparsteck, Sex and Manifest Destiny: The Urge that Drove Americans Westward (2012), 1, 3; Russell McClintock, Lincoln and the Decision for War: The Northern Response to Secession (2008), 25; David Ryan,“Necessary Constructions: The Other in the Cold War and After,” in U.S. Foreign Policy and the Other, ed. Michael Patrick Cullinane and David Ryan (2015), 185-207 (quotation on 193). What I am criticizing here is how imprecise phrasing has contributed to the trope of American westward expansion, not necessarily the content of the mentioned works.


[13]Robert E. May, The Southern Dream of a Caribbean Empire (2002), 173-74.

[14]Howard Jones, To the Webster-Ashburton Treaty: A Study in Anglo-American Relations, 1783-1843 (2017); David M. Pletcher, The Diplomacy of Annexation: Texas, Oregon, and the Mexican War (1973).

[15]“Louisiana Purchase Treaty (1803)” in “The People’s Vote: 100 Documents that Shaped America.” 

[16]Merrill D. Peterson, Thomas Jefferson & the New Nation (1970), 778.

[17]Thomas Jefferson, “Notes on the State of Virginia, Query XVIII: Manners.” 

[18]“Our Documents-Transcript of Louisiana Purchase Treaty” (1803); Roger G. Kennedy, Mr. Jefferson’s Lost Cause: Land, Farmers, Slavery, and the Louisiana Purchase (2003), esp. chapter 13.

[19]Annette Gordon-Reed, On Juneteenth (2021), 18, 23-29, 102-17; Randolph B. Campbell, An Empire for Slavery: The Peculiar Institution in Texas, 1821-1865 (1989).

[20]Rachel St. John, “Contingent Continent: Spatial and Geographic Arguments in the Shaping of the Nineteenth-Century United States,” Pacific Historical Review, 86 (Feb. 2017), 18-49 (quotation on 45).

[21]Andrew J. Torget, Seeds of Empire: Cotton, Slavery, and the Transformation of the Texas Borderlands, 1800-1850 (2015), 262.

[22]Robert E. May, Manifest Destiny’s Underworld: Filibustering in Antebellum America (2002).

[23]Michel Gobat, Empire by Invitation: William Walker and Manifest Destiny in Central America (2018).

[24]Cartoon, Library of Congress, “The Ostend doctrine. Practical Democrats carrying out the principle.” 

[25]Robert E. May, Slavery, Race, and Conquest in the Tropics: Lincoln, Douglas, and the Future of Latin America (2013).

[26]May, Manifest Destiny’s Underworld, 42-43, 260-61. Thomas O. McDonald, in Texas Rangers, Ranchers, and Realtors: James Hughes Callahan and the Day Family in the Guadalupe River Basin (2021), 249-373, makes a persuasive, heavily documented case that Callahan and his fellow raiders crossing Texas’s border with Mexico were not motivated by hopes of recovering African Americans previously enslaved in Texas, while recognizing that such purposes did affect other Texans intruding on Mexico’s sovereignty.

[27]Alice L. Baumgartner, South to Freedom: Runaway Slaves to Mexico and the Road to the Civil War (2020).

[28]James David Nichols, “Freedom Interrupted: Runaway Slaves and Insecure Borders in the Mexican Northeast,” in Fugitive Slaves and Spaces of Freedom in North America, ed. Damian Alan Pargas (2018), 253; Kyle Ainsworth, “Field Hands, Cowboys, and Runaways: Enslaved People on Horseback in Texas’s Plains-Herder Economy, 1835-1865,” Journal of Southern History, 86 (Aug. 2020), 557-600.

[29]Baumgartner, South to Freedom, 208-11.

[30] Conner, “Whitewashing U.S. History.”