It’s just past dawn near San Agustín Plaza, in downtown Laredo, my mother’s birthplace, and the sun is beginning to singe the tips of the lanky cane along the Rio Grande. Already, an unshaded queue of Mexicanos, crossing over for day work or shopping, stretches well beyond the span of International Bridge #1, the city’s oldest, also known as the Gateway to the Americas. And these are just the folks with visas. Uncounted others will have crossed the river surreptitiously under the protective cover of night. Still others could be waiting to cross, arduously hidden away under false truck beds or packed like cargo into crates, hoping luck is with their coyotes as they warily approach the checkpoint. Who knows?

Anything involving Mexico is bound to lead to mystery eventually, so it’s not surprising that the question of the border and immigration is no exception. But the mystery here doesn’t so much involve the border as it does the story of migration itself. The deep subconscious of Mexican culture is full of mythic stories of ancestral migrations, captured in the ubiquitous images of footstep trails that appear in many of the earliest codices that have been preserved. The most important of these myths is the ancient story of the pilgrimage of the tribes who would become the Aztecs. Exhorted by their god Huitzilopochtli to leave their homeland of Aztlán in search of a new home, they uprooted and wandered for years before encountering the promised sign, an eagle standing on a cactus, devouring a serpent. There they founded Tenochtitlán, which later became Mexico City. Since then, it seems that every generation of Mexicanos, indigenous and mestizo, has been searching for a new homeland of great blessings, even if it should require a long journey to find it. It’s an Exodus-like theme that you can trace from the oldest pictographic records of the indigenous world to the modern accounts of the undocumented people captured by the Border Patrol.

An hour passes, and the line barely moves, as the heat of the sun grows more unforgiving, minute by minute. I watch this scene from the balcony of an air-conditioned room in the Hotel La Posada, thinking how every one of those bobbing heads I see could be me. As with many other native Texans, immigration across this increasingly fractious border is a family legacy for me, and a personal issue. My mother’s ancestors first came to the northern hinterlands of Nueva España that would eventually become north Mexico and South Texas sometime in the early 1600’s, and later they were among the families who founded a constellation of villages along the river, including Laredo, in 1755. The U.S.-Mexico border appeared well into their saga, like a haunting wraith of separation laid across lands already long settled by people of an emerging nation.

As an inheritor of this legacy, I can’t count the times I’ve crossed the border—back and forth from Eagle Pass into Coahuila, from Laredo into Nuevo Laredo, from McAllen into Reynosa, from Brownsville to Matamoros, from Presidio to Ojinaga. On my father’s side, my great-uncle Francisco Garcia crossed out of Coahuila at Piedras Negras, fleeing the turmoil of the revolution, sometime around 1914. He later recalled it as a quiet passing across a steel bridge that cost him a nickel, with no customs or border officers asking for papers. Now traffic is perpetually stalled at the bridges as agents scrutinize papers. Innumerable Border Patrol SUVs crisscross the highways and back roads of the region, often as helicopters hover overhead. Drones patrol the skies, seeking crossers who’ve avoided the patchwork cordons of agents, walls, and fences. Soon, we are promised, National Guard troops will arrive to establish forward operating bases to surveil the land, just as in Afghanistan.

Today’s border is a landscape of ghosts, a geography populated with a host of specters from a long, fraught history, all the upheavals of the past five hundred years in our Texan patch of the New World. For decades, immigration policy has found it hard enough trying to close the border to the living. But it is truly powerless to detain the ghosts of the past. They continue to pass freely, some heading north, some heading south. No policing stratagem will ever capture them, nor can we ever fully know the magnetic force they exert upon us.

But what difference might it make if our immigration policy were shaped in full recognition of our complex past? The current debate has emerged from an extremely narrow spectrum of historical awareness. In a recent radio interview, Homeland Security Secretary and former Arizona governor Janet Napolitano observed that “the border is a big and complicated place.” By contrast, in the current tumult over immigration, the matter is often presented in the media as a simple choice between law and anarchy, between protecting American values and identity and abandoning them to a wave of immigrants from the south. Fueled by a spiraling whorl of fear and mistrust, the debate has reached the point that many hot-button issues come to, where they detach from reality and history and begin to create a new, self-justifying mythology.

I had come to the balcony at La Posada in Laredo to try and reattach to reality. In late summer, as the radios and televisions buzzed with discussions of racial profiling and birthright citizenship and amnesty, I set out from my home in San Antonio on a journey through South Texas, where the ghosts of history are as much a presence as the visions of the future. I went in search of those ghosts and in search of the living too, those who are telling another sort of story about migration that makes a full reckoning of the deep history of our contested, shared borderlands.

My first stop was the Kenedy Ranch Museum of South Texas, in Sarita, twenty miles south of Kingsville down U.S. 77. Encompassing 400,000 acres of former Spanish and Mexican land grant territories, the ranch has a uniquely South Texas mestizo legacy that began in the middle of the nineteenth century, when the founder, Mifflin Kenedy, an immigrant from Pennsylvania, married Petra Vela de Vidal, the daughter of one of the oldest Tejano families from that region. Along with the King Ranch, it’s among the most legendary spreads of South Texas. But it’s also home to one of my favorite museums. Installed in the Spanish Revival—style building in Sarita that once housed the ranch’s business office, the Kenedy Ranch Museum’s rooms are filled with artifacts and decked with bright historical murals, accompanied by a rigorous audio tour depicting the good, bad, and ugly of the past four centuries.

The director of this little-known gem of South Texas historical lore is border polymath Homero S. Vera. I first sought him out when I started inquiring into my family’s place in the history of Nuevo Santander, the region of New Spain that included much of the Rio Grande Valley and the northern Mexican state of Tamaulipas. Formerly these lands were known only as las tierras bárbaras de los infieles, “the barbarous lands of the infidels.”

Homero was raised on a ranch in Duval County in the 1950’s, but it might as well have been the 1850’s. Spanish was the family language. The Veras’ rattlesnake-country rancho was the focus of family life. He hunted and trapped with uncles. The family made monthly trips into town for groceries and provisions. A committed ranchero by age five, Homero hated moving into Premont when his dad got a job as a mechanic in town.

Growing up this way gave Homero a powerful desire to help bring the early history of the region to a larger public. But his first chance didn’t come until he was 44 years old, in 1997. After being laid off from a longtime job in a nearby Celanese chemical plant, he used his severance benefits to launch a monthly newsletter of South Texas history called El Mesteño, or “the Mustang,” a reference to the wild horses that once roamed the coastal plains. During the seven years of its run, El Mesteño developed a loyal following, myself included. For anyone interested in the history of this region, it was a treasure trove. A typical issue might include features on the history of specific Hispano surnames of the region; analyses of founders’ lives and early architectural styles; accounts of tequila-running routes to San Diego during the Prohibition era; recipes using local plants and herbs; traditional dichos, or “sayings,” in the Valley; perhaps even a profile of a visiting conjunto band—from Japan. The piquant rigor of these historical briefs quickly earned him the respect of such eminent Tejano historians as Andrés Tijerina, Emilio Zamora, and Frank de la Teja and boosted circulation as high as two thousand before the journal quit publishing, in 2004.

I met Homero in his office at the museum. He was dressed in the denim shirt, jeans, and dusty work boots of a vaquero. A sofa was piled high with children’s drawings of American Indian symbols from a recent school field trip. The walls were hung with a framed satellite photograph of the vast Kenedy Ranch and photos of local wildlife, including one of a white-throated caracara, a bird often called the Mexican eagle. Homero is a born corrector, and this photo occasioned his first correction of the afternoon.

“They say the caracara was actually the bird the Aztecs saw consuming the serpent over the cactus in the Valley of Mexico,” he told me. “Somehow way back there, somebody switched the golden eagle in its place.”

Homero is tall, husky, white-haired, fair-skinned, and hazel-eyed. He speaks quietly in a classic Valley manner, a gentle Texas drawl that still carries the hint of a Spanish accent. Explaining El Mesteño, he said, “I wanted to tell the story as it is, tell the facts as they are, so I began to focus on the stories of the ranches from the original Spanish land grants, beginning with the first surveys of the lands that were later settled, from Laredo to Corpus Christi. In schools, we were taught about the Mayflower and the pilgrims, but we were never taught about that.”

The short version comes down to this, as Homero explained: The lands we now know as South Texas have always been a crossroads of undocumented immigrants, beginning with the indigenous peoples, then settlers from Spain, England and Ireland, Mexico and the United States, among many others. The museum’s murals, painted in 2002 by Mexican-born Houston artist Daniel Lechón, reveal the story of how the intertwining destinies of all those nations played out in the hardscrabble Rio Grande Valley.

We left the office and bumped down a long ranch road, through pastures where oaks mingled with sotol plants, to the house on the La Parra division, where Homero lives with his Mexican-born wife, Leticia, a schoolteacher. In the sitting room, with a ceiling fan keeping time and a repast of nilgai jerky and frosty Dos Equis before us, Homero reflected on the profound transformations in his beloved borderlands.

“The last five, ten years, the border has changed a lot, for the worse,” he said. “And I don’t know if it’s going to get any better.” He described how the experience of undocumented immigration has changed in his lifetime, from its origins in agricultural labor on the ranches of the region to an interval in the more and more complicated labor flows of globalization.

“The migration of the indocumentados is a business now,” he said. “When I was growing up, they would come on their own, mostly rural people who would work on the ranches, gather one thousand dollars, two thousand dollars, and then it was ‘Nos vemos el otro año’ [‘See you next year’]. It’s very rare now to see one individual by himself; it’s always a pack of people in the back of a truck or in the brush, a group of people led by a coyote, heading for North Carolina, Chicago, Houston.”

He paused, his face suddenly looking resigned and wary. “Of course, we need some kind of legislation to allow these people to come here legally and live here and work here, but I don’t know if that’s gonna stop the violence, the trafficking. We need to eliminate the coyote, because the majority want to come and work the correct way.” He grew quiet, with a worried look. “The drugs are a different story.” He told me how his wife had recently seen suspicious-looking black-uniformed individuals somewhere on the road between Riviera and Falfurrias, possibly narcos. The surging war among rival Mexican drug cartels just across the Rio Grande has introduced yet another confounding factor into the long history of migration in the borderlands. Homero never addressed this in El Mesteño, and he now wonders whether it isn’t time to start up the journal again, to inform this new and disturbing chapter.

Night fell and we stepped out into the warm Sarita air. The sky was so limpid that the Milky Way glimmered like a band of pearly embers stretched across the sky. A shooting star tracked a path over us, an augur always regarded in my family as a greeting from the ancestors.

The next morning I set out for Laredo. All along the highways and farm-to-market roads—through Raymondville, La Gloria, Rio Grande City, and San Ygnacio—there were signs of the old agricultural way of life, verdant fields crowded with tall sugarcane stalks, others strewn with cantaloupes discarded during harvest. Abundant rain had left the land green, and flowers bloomed in every direction. Near Zapata, in the aftermath of the early-July flooding, the Rio Grande looked like a broad and tranquil inland sea.

But it was impossible to overlook the changes. I lost count of the number of Border Patrol SUVs I saw along those byways. Searching in San Isidro for the ruins of a Spanish stone noria, a well and aqueduct system, I drove through town and at one intersection saw a man on his knees, his hands cuffed behind his back, his head bowed, while two Border Patrol officers appeared to be finalizing papers for his detention.

The noria was Homero’s idea. The previous night, before we turned in, we’d spent a few hours looking at artifacts from his private collection. First, a faded tricolor flag, dating from the 1820’s, the era of a newly independent Mexican Republic. The insignia showed a Mexican eagle (not a golden eagle) with outstretched wings in the middle, clutching a snake in its beak, only this eagle also wore an imperial crown. The lettering read “Pva. De Texas, San Antonio de Bexar, Primera Brigada de Lanceros a Caballo.” Next, a heraldic banner from an earlier era—red crossed staffs sewed onto a beige silk background, with an ornate rosy brocade border all around. Homero guessed it had probably hung from a standard carried in the vanguard of some eighteenth-century colonial regiment in Nueva España. Finally, he showed me several still-older documents. I looked closely at one, a printed mandate from the king of Spain issued on “24 de Junio, 1757” as an edict on the authority of Viceroy El Marqués de las Amarillas, ordering the immediate and preemptive expulsion of all foreigners from the dominions of Nueva España, a hoary reminder of just how long the issue of illegal immigration has haunted these lands.

After this plunge into the continuum of deep South Texas time, I’d wondered aloud where it was still possible to see physical evidence of the Spanish colonial settlement in the borderlands. Farther north, in San Antonio, the missions have been restored and some have even been designated national park sites. But in South Texas, monuments from the past are harder to spot, hidden down dirt roads in small, forgotten towns. Homero had sent me to go looking for the noria.

I poked around San Isidro, trying to follow his directions, thinking about the past. Much of the current ardor over the border appears to assume that it has always existed. But rather than a divinely inscribed geographic demarcation that descended from the heavens all at once, the current border evolved slowly after its creation in the Treaty of Guadalupe Hidalgo, following the U.S.-Mexican War, in 1848. First came a series of binational commissions made up of American and Mexican surveyors, astronomers, engineers, and cartographers, who didn’t complete their work until 1857. Slowly the sometimes straight, sometimes crooked line of the border emerged out of these expeditions and negotiations, based partly on geodetic surveys, partly on stargazing, and partly on the dodgy cartographic testimony of a palimpsest of maps, which were often at odds with one another.

More than a century and a half later, the boundary still stands. In a time when the borders of “Old Europe” are being erased, the line along the Rio Grande has proved to be among the world’s more stalwart partitions, taking its place on a recent BBC Mundo list of “Los muros que no han caído” (“The walls that have not fallen”). It’s a doleful roll call, including Cyprus, Uzbekistan-Kyrgyzstan, the two Koreas, Botswana-Zimbabwe, and Israel-Palestine, among several others. By comparison with these, the Berlin Wall was an amateur act, a tenuous attempt to bifurcate a kindred nation on ideological terms. Last November I followed the celebrations for the twentieth anniversary of the fall of the Berlin Wall, and I wondered how Americans could feel such an upwelling of compassion for the reunification of a distant land without pausing to think about the wall being erected on their own southern border.

National security is a real concern, but in this history there’s no denying the underlying cultural dynamic, with its generally unspoken assumptions about Texan and American identity. For instance, with Mexican Americans and other Latinos constituting 38 percent of all Texans, how much different would the reaction have been to the governor’s openly talking about secession if his name were not Rick Perry but Ricardo Perez?

Things weren’t always this way. After its official mapping was completed, the Texas-Mexico border remained porous, just as my Uncle Francisco found it, crossing from Piedras Negras to Eagle Pass in 1914, and indeed, the Border Patrol, created in 1915, didn’t become a serious enforcement service until the Prohibition era. Moreover, tightened border security in response to undocumented immigration began in earnest only in the eighties. So, while rooted in a distant past that someone like Homero Vera has illuminated, immigration policy is really an issue of our times, our era of globalization.

Finally, after a long hunt, I found the noria. But the wide, deep well with a series of stone canals radiating out from the center had been left to go to seed. The sandstone and mortar construction was breaking down, and tires, old televisions, and other trash were piled up at the bottom of the stone cistern. This noble structure was being used as a dump.

Later that afternoon I arrived in Laredo and went straight to another museum. Nestled in the historic center, on the south side of San Agustín Plaza, the Museum of the Republic of the Rio Grande stands as yet another reminder of the complex history of the border region. In 1840, after the Texas Revolution, with borders still in dispute and disgruntled north Mexicans rejecting the centralist government in Mexico City, an insurgent movement led by General Antonio Canales created a new, independent republic encompassing north Mexico, present-day New Mexico, and the lands south of the Nueces River. The ill-starred Republic of the Rio Grande lasted only 293 days before it was brutally suppressed by the Mexican army, but the movement that sparked it smoldered for decades, inspiring periodic uprisings for independence in the Mexicano community of South Texas into the early twentieth century.

Housed in a sun-bleached sandstone hacienda that was the headquarters of the short-lived republic, the museum commemorates that period in a series of rooms arranged with historic home furnishings and vitrines exhibiting weaponry, everyday objects, and documents from the movement. Standing before an array of maps that capture all the shifting borders of those times, Rick Villa-real, the former director of the museum, bemoaned how the story has been excluded from American history textbooks, dismissed as a Mexican intrigue. He quickly rehearsed the history of the movement and its links to the U.S.-Mexican War that soon followed, a war that, he noted, remains meaningful for Mexicanos.

“Mexican citizens always seem to have this idea that these lands were stolen by the United States,” he said. “So they should have the right to come over, especially in the Southwest. They feel these lands were originally a part of Mexico, so ‘Why should we recognize these Johnny-come-lately borders?’ It all stems from that war, the U.S.-Mexican War. We’re still feeling the repercussions.”

If that sounds like 162-year-old sour grapes, consider that even Ulysses S. Grant, a veteran of the U.S.-Mexican War, recognized its injustice. The eighteenth president mused in his memoirs that the American Civil War, which erupted two decades later, could be seen as divine retribution for America’s role in the war with Mexico. Grant wrote, “Nations, like individuals, are punished for their transgressions. We got our punishment in the most sanguinary and expensive war of modern times.”

I thought about Grant’s theory as I wandered around Laredo the next day. Are nations punished for their transgressions? How should we understand the current sanguinary episode unfolding across the river, the war among Mexican drug cartels vying for territory in the northern states? The day I arrived, there was a shoot-out in a barrio of Nuevo Laredo, with eight reported killed. But any such news is difficult to confirm. With newspaper and television journalists in Mexico unwilling to risk reporting such events, word spreads virally through Facebook, Twitter, and old-fashioned word of mouth. In the long saga of border conflicts affecting the experience of immigration, this one may be the gravest ever, the latest vexation laid over a tragedy, rooted in an enigma.

“I think the word is ‘incertidumbre,’ right?” asked Maria Eugenia Guerra, an old friend and the founder and publisher of LareDos, an independent monthly news journal. I’d stopped into her busy downtown offices to hear the latest. “The uncertainty of it—we’re in that.” Guerra’s ancestors (some of whom are mine as well) date back to the early 1600’s in New Spain, and her family continues to own land in and near San Ygnacio, from the original porciones, as the Spanish land grants from the 1700’s are widely known throughout South Texas. But for Guerra, along with so many other Laredoans, the widening impact of the narco war has changed everything.

“How will we end the violence?” she asked me. “We’re so far away from what’s really going to happen, and that’s unknown to us, of course, but it has all the markings of a horrible era to come.” She told me she had been considering something previously unimaginable—leaving Laredo, continuing the migration her ancestors began three hundred years ago.

“After centuries, I think—and I’ve never, ever thought this—but maybe my family should move north,” she said. “Maybe this is the next northern migration.”

Nearing twilight in Laredo, I returned to the museum for a few more snapshots. A small group of men were bringing in a load of crates, aluminum cases, and electrical cables, setting up light stands and arrays of what appeared to be scopes of some sort. I thought they were engineers or contractors working on a restoration project in the old building, but they turned out to be the seven members of the Laredo Paranormal Research Society (formerly, and more forebodingly, known as the Paranormal Entity Research Investigation League, or P.E.R.I.L.), a cohort of ghost hunters, all of them law enforcement professionals by day. In other sites around Laredo, the society’s hunters have caught “energy anomalies” in photographs of abandoned buildings, fleeting glimpses of a face in the dark doorway of an old hospital, and faint voices in cemeteries speaking English and Spanish.

They told me that there have been numerous reports of anomalous phenomena in the historic hacienda museum building. Mysterious orbs appear in tourist photographs, audio tour narrations spontaneously begin playing, and, spookiest of all, a crib made of heavy pecan wood was discovered rocking on its own. The night I found them, the investigators were setting up for a 72-hour surveillance, hoping to capture one of the local spirits in an infrared camera or a digital audio recording. I asked if they could discern the immigration status of their etheric quarry—and they replied only with skeptical looks.

I’m serious, I told them. We have this in common: We’re all looking for ghosts.