correction

An earlier version of this article incorrectly quoted attorney Carol Anne Donohoe as saying her law firm applied in February to bring Sandra Ortíz across the U.S. border and was denied. Donohoe says the firm did not apply to bring Ortíz across the border in February; she was referring to another client. The quote has been removed.

SAN DIEGO — Three years, seven months and four days after U.S. immigration agents separated her from her child, Sandra Ortíz was walking through the San Ysidro border crossing Tuesday when she spotted Bryan Chávez.

“My son!” she cried. “I missed you so much!”

They held each other quietly in the center of the pedestrian plaza, the frenzy of the border a blur around them.

Ortíz and Chávez were among the thousands of families separated by the Trump administration in 2017 and 2018 under a policy intended to deter migration. Now they were among the first reunited under the Biden administration — the start of a massive relocation of parents deported by one U.S. president and returned by another. In total, more than 1,000 families are expected to be reunited.

Ortíz, 48, from central Mexico, had packed her bag days earlier: three outfits, a pair of shoes and the birth certificate of her son, whom she hadn’t seen since they were separated at the border in 2017, when he was 15. He’s now almost 19.

Chávez eventually moved in with relatives in Southern California, where he enrolled in high school. Ortíz was deported alone to Mexico.

In the days leading up to the reunification, she could barely sleep.

“I keep thinking about what it’s going to be like. How will I react? How will he react?” she said Monday. “He’s not the same boy I remember.”

The influx of unaccompanied minors at the U.S.-Mexico border stems from crisis in Central America and Trump-era immigration policy. (Blair Guild/The Washington Post)

They’re one of four families to be reunited this week as part of what government officials and immigration lawyers describe as a trial balloon — a test to find the most effective ways to return parents to their children without reviving the trauma they experienced when they were separated. And so it was with some reservation that the lawyers working on their case told Ortíz that the process would involve her returning to the same border crossing where she had been separated from her son.

“Hopefully it’s not a triggering event,” said Carol Anne Donohoe, Ortíz’s attorney, of the law firm Al Otro Lado.

“I think it’s all going to come flooding back to me when I’m there,” Ortíz said. As she walked to the immigration office, she imagined agents handcuffing her again and leading her away.

But this time, they processed her quickly, accepting her humanitarian parole paperwork, leading her to the pedestrian bridge. Chávez was waiting in a red shirt and black jeans and holding a bouquet of balloons that said, “Best Mom Ever.”

Ortíz and Chávez had fled their village in Mexico’s Michoacán state, where it seemed as though everything that could go wrong did. Her husband disappeared in 2010; his body was found two days later with bullet wounds. Then the local cartel delivered the body of their teenage neighbor, Chávez’s friend, dismembered in a bag. And then they began trying to recruit Chávez.

“That’s when we decided to go,” Ortíz said.

It was October 2017. The Trump administration’s “zero tolerance” policy wouldn’t be officially implemented until April 2018, but authorities had already begun separating migrant families at the border.

Ortíz and Chávez turned themselves in at the San Ysidro port of entry and requested asylum. Two days later, she says, they were taken to a nondescript office.

“They told me to say goodbye to my son, that I wouldn’t see him again,” she said. “And then they took him away.”

Ortíz was detained for more than a month with other mothers who had been separated from their children. Like Ortíz, most were unable to communicate with their children during their time in detention. She said Immigration and Customs Enforcement officers told them their sons and daughters would be put up for adoption.

Eventually, Ortíz was told that she had failed her “credible fear” interview, the first step in gaining asylum, and would be deported. She asked for her son to be deported with her, she said, but officials told her it wasn’t possible.

After Ortíz was sent back to Tijuana, she called her older son. José Arturo had migrated to the United States years earlier. He told her that Chávez had arrived in Southern California and the two of them were living together.

Ortíz took a bus back to Michoacán. She moved in with her parents on the outskirts of their town. For weeks, she refused to go outside. She made video calls to Chávez, but they mostly just stared at each other and cried.

“I assumed, ‘This is it. I’ll never see him again,’ ” she said.

Ortíz found a job harvesting lemons, earning about $10 per day, three days per week. She and Chávez settled into a routine of about two video calls a week. She charted his progress from call to call.

First he was learning English. Then he was enrolling in advanced-placement classes. He moved in with his sister, Yeritzel, who had migrated separately to the United States. Then he was graduating high school early. He told Ortíz about his prom and his first full-time job. He ended almost every call by saying, “We’ll be together soon.”

But when he hung up the phone, he said, he would tell his friends: “I wish she was here for this.”

President Biden promised during his campaign last year to reunite families separated by the Trump administration. When he was elected, Ortíz began to wonder whether a return to the United States might be possible.

Al Otro Lado, the law firm, had contacted her and told her to be patient. But her lawyers grew frustrated with the pace of the reunification process.

“We had to keep telling our clients to wait and wait and wait,” Donohoe said.

Last week, the Department of Homeland Security agreed to process the first few returning parents at the border. Ortíz’s flight to Tijuana — her first time in an airplane — was booked. So was a coronavirus test and an appointment with Customs and Border Protection in San Ysidro.

“We are reuniting the first group of families, many more will follow, and we recognize the importance of providing these families with the stability and resources they need to heal,” Homeland Security Secretary Alejandro Mayorkas told reporters Sunday.

A small group of lawyers and advocates, including Donohoe, made arrangements for about three dozen parents, among the first group slated to return. The challenges were many. The passport process in Guatemala, for example, proved painstaking. Some parents had limited cellphone access and could be reached only once a week. Others had developed a deep mistrust of the United States after their separations and worried that parts of the reunification program might be a scam.

Another group of advocates was charged with finding hundreds of separated parents who have not been located since their deportations. Four-hundred and sixty-five remain “unreachable.” A fraction are probably living with the children in the United States, according to the American Civil Liberties Union.

In June 2018, a judge ordered the Trump administration to reunify separated families within 30 days, and hundreds were. But by then, hundreds more had already been deported without their children.

Because the Trump administration kept little contact information for the parents they had deported, advocates were left to fund radio advertisements that aired across Central America.

“If you or someone you know was separated from a child at the border with the United States between 2017 and 2018,” the narrator of one ad said, “this information will interest you.”

A few days ago, before Ortíz left for the border, Chávez gave her a video tour of her future home, including two neatly made beds next to each other.

“How pretty,” she said, smiling at the screen, which then flashed again to her son’s face, more mature than she remembered, with a dark shadow of facial hair.

“He looks like a man,” she thought.

And then she thought: “He looks sad. He’s not the same son I had. This whole thing has changed him.”

Asked to envision the weeks after the reunification, she paused.

“Being together again will be beautiful,” she said. “But it might not be easy.”

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