The international boundary between United States and Mexico is a continental border that is 3201 kilometers long running from Tijuanain the west to Brownsville in the east.The border runs through diverse terrain including rivers, built-up urban areas, uninhabitable deserts and the ocean. These include part of the Rio Grande and the Colorado River deltas. It also includes conurbations of various border crossings that include San Diego, Otay Mesa, Andrade, San Luis, Naco, Douglas, Chihuahua, El Paso, Roma, Rio Grande City, Los Ebanos, Los Indios, among other cities and towns. It also crosses huge tracts of the Sonora and Chihuahua deserts. The border also includes maritime boundaries of 29 kilometers in the Pacific Ocean and 19 kilometers in the Gulf of Mexico (McCarthy, 2011).
The US-Mexico border region extends to cover 60 kilometers north and south of the boundaries as well as 60 kilometers into the Gulf of Mexico and 60 kilometers into the Pacific Ocean. With a population of about 12 million people, the region includes the four US states of California, Arizona, New Mexico and Texas as well as the six Mexican states of Baja California, Sonora, Chihuahua, Coahuila, Nuevo León and Tamaulipas. Texas has the longest stretch of the border in the US whereas Chihuahua has the longest stretch in Mexico.With about 350 million legal crossings per year, the US-Mexico border is the most frequently crossed international border in the world. There are 330 ports of entry along the border and 48 border crossings that include walkways, roads, railroads and ferries(St John, 2012).
The boundaries, border region and ports of entry were mainly shaped by three major treaties between US and Mexico – the 1848 Treaty of Guadalupe Hidalgo, the 1889 International Boundary and the Water Commission and the Boundary Treaty of 1970.
Before mid-16th century, the US-Mexico border region had sparse population and was generally considered no-man’s land. Discovery of silver in the region around mid-16th century led to various diverse people, including colonizers, arriving to the region. The region was considered part of the Kingdom of New Spain until the 19th century when the US acquired the Louisiana Purchase from France and started pursuing the Manifest Destiny(St John, 2012).
Meantime, Mexico became independent from Spain, aperiod of political instability that saw Mexico attempt to buffer itself from a northern invasion by encouraging settlement in the Texas region. However, the Texas region declared independence from Mexico in 1836, with the US consequently annexing Texas in 1845. This led to the Mexican-American War of 1846-1848 that ended with the Treaty of Guadalupe Hidalgo that established the middle of the Rio Grande as the border. The treaty say Mexico lose more than half of its territory and abandoning of disputes over territories. Creation of the current United States–Mexico border was completed five years later with the Gadsden Purchase. The International Boundary and Water Commission (IBWC) administers border disputes, though critics view the body as having been overtaken by political, environmental social issues (Miller, 2014).
Political, economic and social factors
Economic development of the US-Mexico border region, including the boom period of 1876-1910, is mostly attributed to investment from the United States. The boom years are associated with increased mining, building of railroads and enabling governments’ policies(McCarthy, 2011). The Mexican Revolution that began in 1910 curtailed this development in the border region, especially on the Mexican side.
Unequal development has given rise to security issues through legal and illegal migration, especially south-north migration. Illegal movement of people, weapons and drugs is especially a concern, with the United States Border Patrol (USBP), the largest federal security organization, taking a lead role in controlling this(St John, 2012). The Secure Fence Act of 2006 provided for construction of a high security fence to cover 1100 kilometers of the border, though costs saw it abandoned after over 600 kilometers. The incoming President Trump administration proposes to build a wall along the entire border paid for by Mexico. Overall, there has been decreasing illegal movement across the border, a factor attributed to tougher security measures and lesser rewards.
1983’s La Paz Agreement commits the US and Mexico to protect the environment in the border region. Under the agreement, there have been programs to curb environment destruction caused by rise in maquiladora industries and related factors such as population explosion, strained infrastructure and lax regulations(Miller, 2014).
Despite the security issues, there is high movement across the US-Mexico border because of the two countries’ interconnectedness in economy, culture and ethnicity. There are people who cross the border daily for work, school and visits; with the San Ysidro Port of Entry between San Diego and Tijuana being the busiest in the world (St John, 2012).