And many families whose whereabouts were known have since moved or changed phone numbers, compounding the challenge of possible reunification.

Further complicating the task is that most migrants come from Central America, and three countries there — Guatemala, Honduras and El Salvador — have experienced lockdowns during the pandemic, as well as widespread internal displacement from two hurricanes, Eta and Iota.

“We must find every last family and will not stop until we do,” said Lee Gelernt, the lead attorney for immigrant rights at the A.C.L.U.

But the process has been “extremely difficult and slow,” he said, adding that “many of the parents can only be found through on-the-ground searches.”

During a visit to a small Guatemalan town, a Times reporter learned of three parents who said they were forcibly separated from their children by U.S. border officials in 2018 and then deported. Two had already made the perilous return trip to the U.S., spending $15,000 on a journey to reunite with their children in Florida.

“They returned for the kids, because they were left alone there,” said Eusevia Quiñónez, whose husband, Juan Bernardo, left with his older brother for Fort Lauderdale, Fla., on Jan. 8. “Thank God, they arrived OK.”

Another father, Melvin Jacinto, was contacted by KIND, a children’s defense group, more than a year ago, but he doubts they will be able to help him. He again wants to try to enter the United States to reunite with his son, Rosendo, in Minneapolis and to find work to support his family. He said talking on the phone with his son, who turned 18 last month and from whom he has been separated for three years, is emotionally difficult for him. He can’t help but cry.

“It’s like I’m traumatized or something,” Mr. Jacinto said. “I’m not good. I don’t sleep, not at all.”

Psychologists working with separated families say that family reunification is just one step in the healing process, and that the parents have as much need for mental health counseling as the children. Many parents blame themselves for the separation, and after reunification the children, too, often blame the parents.

David, who has suffered from stress-induced gastritis and other health complications since the separation, said he had also considered hiring a smuggler to get back to the U.S. to reunite with Adelso.

“I need to see my son,” he said. “And he needs me.”

View Source