The U.S.-Mexico border is best understood not as a demarcation line but as a borderland where the cultures and societal norms of each country coexist. This land currently is clearly controlled by the United States, though historically it has changed ownership multiple times. The evolution in this borderland area will be one of the defining characteristics of the U.S.-Mexico relationship for decades to come.

  • By nature, borderlands are a source of conflict between nations, though there are periods of dormancy and peace.
  • The land in question helps protect the U.S.’ strategic interests.
  • U.S. ownership of the area has lasted so long because it has been the uncontested power in the region.
  • The demographics in Texas illustrate what the borderland looks like today.


The U.S.-Mexico border is one of five major geopolitical fault lines in the world today. By fault line we mean an area with permanent underlying tensions that periodically erupt in conflict. The frequency and intensity of such eruptions vary with each location. Currently, the U.S.-Mexico border fault line is dormant, but it won’t stay that way forever.

The potential for conflict along this fault line stems from the fact that this region is a borderland. Borderland refers to an area between two or more well-defined cultural spaces that are socially and culturally heterogeneous but controlled politically by one power. Mexicans on the U.S. side of the borderland feel less pressure to assimilate. They can more readily recreate their home culture and maintain close connections to people in Mexico.

Aerial Views Of The U.S.-Mexico Border On The Rio Grande

The Rio Grande snakes westward, forming the border between Mexico (L), and the United States on May 20, 2013 near Havana, Texas. The Rio Grande Valley area has become the busiest sector for illegal immigration on the entire U.S.-Mexico border. John Moore/Getty Images

Historically, borderlands tend to change hands multiple times. The ruling power of a borderland is the country with the most political and military might. In the case of the U.S.-Mexico border, the last time this area officially changed hands was at the end of the Mexican-American War in 1848. Since the end of that war, Mexico has not been in a position to challenge the U.S. However, an imbalance of power does not eliminate the borderland concept, as the underlying tensions between the two nations remain.

Both sides of the U.S.-Mexico border embody the borderland concept. For the purposes of this article, we focus on the U.S. state of Texas because its history and present-day population best illustrate the borderland concept. Looking at the evolution of Texas as a borderland reveals underlying tensions between the U.S. and Mexico. This sets the backdrop for the current (and future) political, social, economic and military dynamics between the U.S. and Mexico.

The Spanish and Mexican Eras

Spain was the original non-native power to control the Texas territory, and from the beginning, holding this territory posed a huge strategic challenge. The viceroyalty of New Spain was a vast territory, claims to which were legitimized by the presence of colonists. The ability to settle the territory would ultimately mean the difference between keeping or losing the Texas territory.

After the arrival of European settlers in North America in the 1600s, the Texas territory served as a key buffer zone between regional powers. The European powers in question were Spain, France and Great Britain, all seeking to establish territorial claims in North America. Spain was primarily interested in the silver mines in Zacatecas. Spain did not view Texas as a critical territory, but rather as a buffer against the French and later the English. Thus, Texas and the northernmost part of Mexico were conceived of as a borderland from the beginning.

While most of modern Texas lay within Spanish territory, up until 1763 a portion of modern east Texas was in the hands of the French. After losing the Seven Years’ War, France divided its North American territories between Britain and Spain. The former received French claims east of the Mississippi River and the latter claims to the west.

For the time being, Texas lay firmly with Spanish territorial claims, at least according to maps. However, the Spanish government still faced the strategic challenge of settling such a large area with military posts and colonists. In 1790, New Spain’s population was just over 5 million, with the majority concentrated in the central part of present-day Mexico. The settlers of peripheral New Spain flocked to areas that promised precious metals rather than establishing ranches or farmland. According to the 1793 census, California was home to about 12,500 people, about 31,000 lived in New Mexico and Texas had a mere 5,000 residents. This was a real problem.

The pressure to fill this space grew with the U.S. purchase of Louisiana in 1803. For the U.S., the Louisiana Purchase was a geopolitical game changer – and Spain understood this. The U.S. was assigned ownership of the Northwest Territory (today the states of Ohio, Indiana, Illinois, Wisconsin and part of Minnesota) in the 1783 Treaty of Paris. By 1800, it had not only settled this territory but adopted new states. But this land could not be fully exploited because the Mississippi River system remained outside U.S. control.


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The Louisiana Purchase gave the U.S. control of this coveted, navigable river system and the strategic port of New Orleans. Two great rivers, the Missouri and the Ohio, flow into the Mississippi. They are joined by other smaller but significant rivers, which flow into the Gulf of Mexico. The navigability of this system means that virtually any agricultural – and later mineral – production between the Rockies and Appalachians could be exported inexpensively via the New Orleans port.

Spain then found itself sharing a border with the rapidly expanding U.S. This was problematic for two reasons. First, European wars had weakened Spain, particularly its famed armada. Second, Spain’s ownership of the Texas territory was called into question. When Spain agreed in 1800 to return the Louisiana territory to France in exchange for parts of Italy, land boundaries of this territory were not specified. The U.S. argued Texas was included in the Louisiana Purchase, while Spain claimed its continued ownership of Texas. In 1819, the U.S. and Spain signed the Adams-Onís Treaty, which said the Texas territory would remain under Spanish control while the U.S. took control of Florida.

Spain followed up the 1819 agreement by issuing land grants to settlers. When Mexico achieved its independence from Spain in 1821, the new Mexican government passed legislation to support the continued colonization initiative. The law was updated in 1823 with the shift to the federal system.

These immigration laws paved the way for settlers to receive land from the Mexican government in exchange for establishing a town, settling up local governance and organizing land grants among the settlers. Tax breaks, reduced trade barriers and other privileges were also afforded to help facilitate the settlement process. This attracted ambitious entrepreneurs from the U.S. Mexico’s hope was to absorb the new settlers into the existing country.

At this point, Mexico needed Texas as a buffer from the Comanche people, who were the dominant power in the region. A buffer with the U.S. was secondary. The Comanche were raiding through the Great Plains and into Texas. At first, Mexico greatly encouraged Anglo migration into Texas because it put people between its settlers and the Comanche.

On paper these settlement laws balanced the need for attracting immigration with the need to preserve assimilation under Mexican rule. The governing constitution at the time of the colonization law established Catholicism as the only religion in the territory. Mexican citizenship was automatically issued after three years of residency. The law allowed slaves to enter the territory but declared any descendants free.

In practice, this balance was hardly achieved, since the Mexican government lacked effective means to enforce the law. The newly arrived Anglo settlers were predominantly Protestant and had no intention of converting to Catholicism. Furthermore, they supported slavery and did not want to change their practices. They also interpreted the settlement powers granted to them as a license to govern more autonomously than the Mexican government intended.

Mexico’s government was too weak to enforce its rules in the Texas territory. Weak rule of law is very characteristic of borderlands. The populations in these locations live in a gray area. Ultimately, this laid the groundwork for losing the land. This weakness stemmed from the lack of manpower as well as the fact that Mexico had to deal with continued Spanish attempts to regain the territory for the remainder of the 1820s. As a result, native populations and Americans were able to regularly raid Mexican lands. At times they succeeded at capturing territory. Many Americans did not recognize the 1819 treaty and stood by the claim that the Texas territory should fall within U.S. borders. Secondly, the absence of a central authority led to lawlessness, and Anglo settlers illegally assumed ownership of lands and powers normally reserved for the central government or military.

In a final but futile attempt to draw Texas into Mexico, the Mexican government passed a series of immigration laws in April 1830. The laws limited immigration of U.S. citizens, forbade further introduction of slaves, placed more government controls over the settlers and promoted coastal trade. The Anglo residents in Texas found these terms unacceptable.

From this point onward, tensions between Anglo settlers in Texas and the Mexican government grew and the U.S. government saw an opportunity. Since the loss of Texas to Mexico in 1819, the U.S. remained concerned about the proximity of the Sabine River border (only a couple hundred miles long) to New Orleans. U.S. President Andrew Jackson sent confidant and War of 1812 veteran Sam Houston to encourage an uprising in Texas. Texas declared itself an independent republic and war ensued.

Mexico had the larger army, better equipment and, in many ways, better commanders. However, it faced three disadvantages that would cost it the war. First, Gen. Antonio López de Santa Anna’s military faced unrest on two fronts; Mexico decided to quell unrest in Yucatán in the south before dealing with Texas in the north. Second, the military had to pass through the desert to reach San Antonio. This exhausted the troops. Third, it followed the European military model, which created a hierarchical chasm between the officers and soldiers. The army Santa Anna brought north into Texas had well-trained generals and good artillery, but the foot soldiers were poorly equipped indigenous people without training.

When Santa Anna crossed the northern deserts, his army faced the coldest winter in years. By the time soldiers reached the Alamo, they were exhausted yet managed to prevail. The commanders didn’t care about the troops and made their way east to San Jacinto… where the Texans defeated them.

The U.S. Takes Over

Texas declared itself a republic, which lasted from 1836 to 1846. During this time, the Texas government sought U.S. statehood. At first, the U.S. denied the request to avoid a confrontation with Mexico. It also wanted to avoid the domestic turmoil that would arise by adding a slave state into a country where slavery was becoming a divisive issue. Eventually the U.S. agreed to give Texas statehood, which provided the U.S. with a large buffer zone to protect the strategic port of New Orleans.

With Texas acquired, the U.S. could then pursue territorial expansion westward. This led to the Mexican-American War. This war ended with Mexico ceding massive territory to the U.S. and the demarcation of the modern border. From the end of the war in 1848 to the present day, the U.S.-Mexico fault line has remained relatively dormant. This is largely due to the fact that Mexico remained weak throughout the 20th century as it dealt with multiple internal conflicts.

Simultaneously, the U.S. enjoyed strong economic growth and military advancement. Though the fault line has been dormant, the ebb and flow of the population in the Texas borderland is as strong now as it was 200 years ago. While Texas is now part of the U.S., it is still home to many Mexicans and people with Mexican origins. This situation is essentially the reverse of what the territory experienced in the 1820s and 1830s. Such a shift is the very nature of a borderland.

A look at the demographics in Texas shows a strong Mexican presence. According to the Pew Research Center, in 2014 Texas had 4.5 million immigrants, of which 56 percent were born in Mexico. U.S. Census Bureau statistics from 2015 show that 38.8 percent of Texas’ total population of 27.5 million were registered as Hispanic. Being Hispanic is by no means synonymous with being Mexican or of Mexican origin. However, Texas’ proximity to Mexico has strongly impacted immigration patterns in the state such that the vast majority of Hispanics in Texas have ties to Mexico. For example, a second Pew Research Center study found that of the eligible Hispanic voters in Texas, 87 percent were of Mexican origin.

Perhaps even more illustrative of the borderland phenomenon in Texas is the prevalence of the Spanish language. Only 27 percent of eligible Hispanic voters in Texas speak strictly English at home. However, when asked about speaking Spanish in the home, the figure soared to 72.7 percent of all eligible voters. It was not clear what portion of this population spoke both Spanish and English in the home versus those who spoke exclusively Spanish. In a country known for having a monolingual population, the widespread use of Spanish is another strong demonstration of Texas’ status as a borderland.

In addition to demographics, Texas’ economic livelihood is also intimately bound to Mexico. Texas and Mexico share 1,241 miles of border, along which there are 28 crossings. These border crossings are essential to the transport of Mexican goods into the U.S. Over 80 percent of Mexico’s exports go to U.S. markets and a nearly equal percentage of Mexican goods enter U.S. markets via roadways.


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Mexico is by far Texas’ largest trading partner, with exports of goods from Texas in 2015 valued at $92.5 billion. This is more than triple the value of goods exchanged with its second largest export partner, Canada. Texas imports from Mexico in the same year totaled $84 billion. In this case, the amount was more than double the value of goods exchanged with Texas’ second largest import partner, China. The majority of foreign direct investment (FDI) into Texas comes from Western Europe, and Mexico is not a top contributor to FDI received by Texas. However, in terms of FDI paid out by Texas, Mexico is the fourth largest destination by projects (39) and second in capital expenditure ($5.28 billion).

These ties are also deep on a more tactical level. There are many integrated supply and production chains between Texas and Mexico. This is best exemplified by the automotive industry, which has developed a region known as the Texas-Mexico Automotive SuperCluster. This cluster consists of Texas and four Mexican states near or along the Texas border. Input materials, parts and finished goods go back and forth across the border among 27 vehicle assembly plants. Close cooperation is also forming in the area of exploration and extraction of shale gas deposits near the border.


The area north of the U.S.-Mexico border is not like the rest of the U.S., and the area south of the border is not like the rest of Mexico. But the borderland is a shield, and the shield is all that most people on either side tend to see.

The border shielded Americans from a real understanding of Mexico. The experiences of the 1830s and 1840s defined American perceptions of Mexico. The American view of Mexico grew from images of Pancho Villa and Santa Anna – men renowned for being ignorant, brutal and dangerous. Today, this image lives on because Mexican drug cartels have played a pivotal role in shaping perceptions of Mexico.

The same experience has also shaped the general Mexican view of Americans. They are seen as aggressive and unruly cowboys with little regard for authority. Today, this image lives on through students partying during spring break and civilians’ ability to own and carry firearms. Neither image accurately reflects the entire population of the nation. However, it is no coincidence that both perceptions involve an element of lawlessness since that is also characteristic of borderlands.

The Mexican fear of the U.S. is not unreasonable. Nor is the American fear of Mexico. There is a deep history between the two nations, a history that regenerates in different ways at different times. While time and means may vary, the borderland remains the location where any future eruption of tensions will start.