I grew up on the border between the United States and Mexico, near the boundary line that starts at the Pacific Ocean and weaves east toward the Gulf of Mexico. My parents, who are both from Tijuana, met in that city in the late 1970s while my father was home from California’s Central Valley, where he was a field worker. They decided to build a family across the border in San Diego, and that’s where I was born.

It was a time when such a relocation was less an international move and more a matter of switching neighborhoods. The border was one place. More than 100,000 of us crossed in either direction every day. My life was shaped by these comings and goings: During the week, we’d go to school and work in San Diego; on weekends and holidays we’d head south for a birthday or a wedding, or to have dinner with my grandmother Esperanza. She was a retired nurse who lived on the steep hillsides of Colonia Libertad, right alongside the boundary. From the front doorstep of my childhood home on Z Street, we had a view of San Diego Bay and its naval ships. We could also see Tijuana in the distance, its lights like multicolored stars at night.

Crossing the border was made possible by my privilege. On my family’s returns into San Diego, all we had to do was smile and declare “U.S.!” when a border agent asked our citizenship. We were brown-skinned Americans, and no other proof was needed. This was the 1980s, and others crossed just as easily with the shopping and tourist visas that were readily handed to Mexicans born in the region. Back then, there was nothing to fear on the border if there was nothing to hide.

But in 1994, just before I turned 14, this began to change. That October, the Clinton administration reinforced the border near San Diego with more fencing and more agents; the number of immigrants from Mexico was increasing due in part to the passage of the North American Free Trade Agreement. Then came September 11, 2001, and the resulting frenzy over border security and deporting criminal foreigners. I was in college by that time, and I resisted the notion of a tightening line, going back and forth as I always had. I’d picked up bar-hopping, and because there was nothing remotely as purifying as a long boozy night in downtown Tijuana, I ventured with friends or cousins to Plaza del Zapato, a city block full of techno and alternative clubs. We’d drink beer after beer while dancing to Depeche Mode and Maldita Vecindad. Sometimes I’d bump into Tijuana-side cousins doing the same, and our parties would merge.

JEROME SESSINI/MAGNUM PHOTOS

And yet, crossing back, I couldn’t escape how the border was being militarized right under our noses. A few years later, we watched as a triple-layer fence went up around parts of San Diego; in 2006 we’d hear on the news about George W. Bush’s plan to extend the fence all the way through Texas. Agents now dressed in heavy vests, with earpieces and gloves. Tall floodlights shone into Mexico along the Tijuana River, sometimes illuminating groups of men huddling in concrete channels. IDs became mandatory for re-entry. The vehicle lines at the San Ysidro port grew exponentially, snaking into Tijuana’s side streets—sometimes into Colonia Libertad, in fact.

There were deeper costs. The fence influenced our daily plans. Cousins of mine in Tijuana trained themselves to wake up at 4 a.m. to accommodate the lengthening wait times at the border and arrive for the morning bell at their schools in San Ysidro or Chula Vista. It also imposed quiet but prolonged divisions in my family. Relatives who had made their lives in San Diego, raising American children, could not travel to Tijuana because they had not become U.S. citizens and might not be allowed re-entry. Others lost their U.S. visas—for, say, a run-in with the law as teenagers—and moved to Tijuana, unable to secure the paperwork to return to San Diego. The border became a knife, slicing through the region, changing how we related, how we thought about the future. We adapted by creating parallel events on each side—dual baby showers, dual birthdays, dual weddings—sometimes even on the same day. For the most part, this worked well. But for someone like me, who had been born in the U.S. and whose parents had become U.S. citizens, the wall remained an almost comical idea. How could any sort of fence cut through who we were?

For many of us, there was one place where these wounds could be salved. Friendship Park, located west of the San Ysidro entry port, is a plaza that surrounds Monument 258, the white obelisk that marks the western end of the boundary between the U.S. and Mexico. Also known as Friendship Circle, the park was inaugurated by first lady Pat Nixon in August 1971, back when the border was barely defined by a barbed-wire fence, and it was intended to serve as a symbol of binational fraternity. “May there never be a wall between these two great nations, only friendship,” Nixon declared at the park’s dedication. Even after the barbed wire was replaced by gigantic steel bars, the area remained a place of connection. For years, those who had loved ones stuck “on the other side,” north or south, could meet at the plaza, touch through the bars, and gossip or laugh or share news.

I did not visit Friendship Park myself until 2011, when I attended a 40th anniversary celebration of the plaza with my mother. The Department of Homeland Security, citing a need to make the fence even more secure, had closed the space in 2009, reopening it only for this one-day event. The park is where Southern California meets Baja California, so of course it is a beautiful place—the breeze sweeps onshore over the rocks, waves crash up against the fence that stretches into the sea. But perhaps I should have expected that Friendship Park would have lost its hospitable sheen by then. To reach the plaza, visitors had to ride in a shuttle for about a mile over a largely submerged mud lane. Once there, the triple fencing created a sort of no man’s land; at the boundary with Mexico, an imposing metal mesh—preventing all physical contact except for the skin of a fingertip—had been installed on the bars.

The U.S. Border Patrol had designated a sort of corralled-in space for us to see into Tijuana, and my mother and I stood there, with a handful of other families and some border activists. We listened to U.S. officials make a speech or two. The space was small and uncomfortable, and I felt as if we were cattle left out to bake in the heat. On the other side of the mesh, an entirely different scene was playing out. In Tijuana’s half of the park—an open, unmonitored stretch of beach—we could hear roaming musicians playing trombones and tamboras, smell shrimp being grilled in stalls along the boardwalk, and see people dancing—actually dancing—in the sun. Mexican officials had set up a tent and a podium, and a few city council members from Tijuana waved hello. My mother and I shared a glance.

And then we decided to make use of our privilege.

We got back in the car and headed south on Interstate 5 so we could join the party on the other side. After a quick curvy right over the Tijuana River, and then a drive along the fence in Mexico, we arrived at the Tijuana beach in about 25 minutes. We parked near the old bullring overlooking the shore, and approached the fence. On this side, the boundary was painted with bright murals, and marked with crosses bearing the names of people who had died trying to cross. We peered through the fence again. We could hear a few speakers but not much. The mesh made it hard to see. A couple of people on the U.S. side recognized us from minutes earlier and waved with half-hearted smiles. They looked trapped.

Later I would think about how easy it was for me to exercise both sides of my identity like this—and how my mother, who received citizenship in the Reagan administration amnesty of 1986, was able to return home that same night, to watch the Tijuana evening news from the comfort of her living room in San Diego. There are so many families for which this isn’t true. Maybe certain loved ones have crossed illegally or overstayed a visa, and now are forced to remain in place as they await citizenship papers. Maybe relatives in Mexico cannot visit because they have been denied a tourist visa or do not have the means to travel. Or maybe a family member has been deported, with no way to re-enter. These deportations have increased over the past decade, leading to the removal of about 3 million people. The number of parents who were deported between 2003 and 2013 but have children who are U.S. citizens falls somewhere between 740,000 and 925,000, according to a report from the Urban Institute and the Migration Policy Institute. That’s a lot of separated families—roughly the population of Austin or San Francisco. And the one place where any of them have a hope of seeing each other again is Friendship Park.

The documentary “Monument/Monumento,” by filmmaker Laura Gabbert, shows one such reunion, between members of the Ascencio family. Friendship Park reopened to the public in 2012, but access on the U.S. side remains restricted to a few hours on the weekends. The family’s patriarch, who sits in a wheelchair, has traveled some 1,500 miles from Mexico City to be there; his children and grandchildren have driven seven hours from the Central Valley. They have not seen each other in person for two decades.

To enter this impersonal and fortified space, under the watchful gaze of border sentries and cameras, is to willingly lay yourself bare: your love, your longing, your pain. And yet that vulnerability only gets you so close. The intimacies you crave—to smell your daughter’s hair, to squeeze your father’s hand—are impossible. All the questions you have, accumulated over years, are unanswerable in a mere few minutes. And those minutes are precious, so instead you search for your loved one’s eyes through the tiny gaps in that mesh. You smile wide so he or she can see. Here you are at last, face to face, but not together.