Fracturing landscapes: a history of fences on the U.S.-Mexico divide

This past spring, I traveled to Otay Mesa, a small community in the southeastern section of San Diego that sits on the U.S.-Mexico divide. As a border historian, I’d traveled down to see the prototypes for the wall that Donald Trump has promised to build—the wall that looms large and hangs over the other disturbing headlines of border enforcement and family separation that have dominated our newsfeeds in the past few weeks. There were eight prototypes, some solid walls, others more like enormous steel fences, all of them were extremely tall. After I got a good look at them, I decided to travel west along the border toward the Pacific Ocean to see what I would find. I knew that fences would line the border the entire way, but even as a historian of border fences, I was surprised to see just how many kinds of fences were there. In the short, roughly ten-mile stretch, I saw nearly twenty different fence designs made up of at least six different kinds of materials. In one place, there were four fences still standing; each fence representing some previous phase of construction and a stark reminder that Trump’s prototypes aren’t new at all, they are part of a long historical trend.

The border at Otay Mesa, in fact, is the site of the very first federally funded border fence, planned in 1909 and completed in 1911. This fence, made up of four strands of barbed wire, was built by the Bureau of Animal Industry to stop the movement of cattle ticks that had been responsible for a widespread cattle disease in the United States. Knowing the tick was the disease vector, the U.S. Department of Agriculture (USDA) oversaw a campaign to rid the United States of the bug. As it turned out, any cow or steer that was exposed to the tick as a calf was immune to the disease, but if southern cattle moved to the north where the tick was not endemic, it infected unexposed cattle. The effort was successful, but because the tick was endemic to all of Mexico, Mexico did not need to get rid of the parasite. As such, any time cattle crossed the border, officials had to worry about the re-introduction of the tick. To keep cattle from Mexico from coming into the United States, the USDA built the first border fence.

Until the middle of the twentieth century, U.S. officials built fences for cattle and the ticks that they carried. Over time, though, fences became tools to control and restrict human migration. In the second half of the twentieth century, rising xenophobic concerns over the number of Mexican and other Latin American immigrants entering the U.S. led to the passage of a series of immigration laws. Most notable among them were the 1965 Immigration and Nationality Act, which limited the number of people who could enter the United States from the Western Hemisphere for the first time (and thus limited the number of Latin Americans), and the Immigration Reform and Control Act of 1986. None of those laws fully worked to stem the flow of immigrants though, and so each one was eventually supplemented by border fences. “Securing the border” became a standard line for nearly every politician and fences grew in length and height each decade.

But no matter how high or how long, fences have failed to stop the flow of migration. As Sam Truett argued in his 1997 article in Environmental History, “Ever since the border was mapped in 1854, the American West and the Mexican North have been linked by economic and cultural lifelines extending deep into their respective territories.” Their environments, too, are inextricably linked and no fence can sever those ties.

What fences have done is create and then exacerbate both an environmental and a humanitarian crisis. As fences have grown, they have diverted human traffic through some of the most dangerous landscapes in the Sonoran Desert. In October of 2006, the Bi-national Migration Institute reported that between 1990 and 2003, the Pima County Examiners Office saw a huge rise in the number of deaths along the entire border, many of which occurred in the Arizona-Sonora Desert. According to the report, between 1990 and 2005, the Tucson Sector alone faced a 20-fold jump in known migrant deaths alone, all due to the “funnel effect” of the expanding structures. The fences have also destroyed the natural environment by fragmenting habitats and blocking border crossing by some of our most valued wildlife.

As I argued in my own recent piece in Environmental History, “In the context of this larger history of construction at the border, past and present building projects provide an opportunity to look to history to understand potential outcomes of Trump’s proposed wall: put simply, history tells us that it will not work and that it will do more damage than good.” Human death and environmental degradation are on the rise all around the U.S.-Mexico border and, given the prototypes standing tall near the original site of the first border fence, nothing suggests that that gross destruction of the environment and disregard for human life is going to stop any time soon. Perhaps it’s time to learn from our previous mistakes.

Featured image credit: By Staff Sgt. Dan Heaton, U.S. Air Force. Public domain via Wikimedia Commons.