On April 6, 2018, Attorney General Jeff Sessions ordered federal prosecutors on the Southwest border to prosecute every illegal-entry case referred to them, a policy he called “zero tolerance.” On May 4, Homeland Security Secretary Kirstjen Nielsen signed a memo citing “recent presidential direction and guidance from the Attorney General” and directing Border Patrol to refer for prosecution all adults who crossed illegally, including parents traveling with children. Prosecuting those parents meant taking their children. The Justice Department's inspector general later called it “a change in long-standing DOJ and DHS practice.” Sessions said it publicly in San Diego on May 7: “If you are smuggling a child, then we will prosecute you and that child will be separated from you as required by law.” No law required it.
It had been tried first. In a 2017 pilot in Border Patrol's El Paso sector, about 280 families were separated, including parents of infants, according to the DOJ inspector general, who found that department leadership did not act on what the pilot showed before taking it nationwide. In a May 11, 2018 call with border prosecutors, according to their notes, Sessions said: “we need to take away children; if care about kids, don't bring them in.” On May 22, Deputy Attorney General Rod Rosenstein told them, per the notes, “AG is clear: Prosecute parents if DHS decides to separate families.” White House Chief of Staff John Kelly told NPR that “a big name of the game is deterrence,” and of the children: “The children will be taken care of — put into foster care or whatever.” On June 17, Nielsen tweeted, “We do not have a policy of separating families at the border. Period.”
The government did not track who it separated. DHS estimated that Border Patrol separated 3,014 children between May 5 and June 20, 2018; its own inspector general reported that, without a reliable record of family relationships, “we could not validate the total number of separations, or reunifications.” In the Rio Grande Valley sector, children were held past the 72-hour limit at least 564 times, and one child for 25 days. The HHS inspector general found that “thousands” of children had been separated and released before the court intervened and that the total “is unknown,” and that separated children “exhibited more fear, feelings of abandonment, and post-traumatic stress than did children who were not separated.” One facility director told investigators, “Every single separated kid has been terrified.”
Trump blamed others. “I hate the children being taken away,” he said on June 15, adding, “The Democrats have to change their law. That's their law.” His June 20 executive order said, “It is unfortunate that Congress's failure to act and court orders have put the Administration in the position of separating alien families to effectively enforce the law.” The order “largely curtailed” the practice, the DOJ inspector general found, but did not end it: HHS's inspector general counted at least 118 more separated children referred to its care between July 1 and November 7, 2018. Reunification came from a court. On June 26, Judge Dana Sabraw ordered the families reunited, describing “a chaotic circumstance of the Government's own making” and finding that migrant children were “not accounted for with the same efficiency and accuracy as property.” Trump kept defending the idea: “If they feel there will be separation, they don't come” (October 2018); “However, if you don't separate, FAR more people will come” (December 2018); and at a CNN town hall in 2023, “If a family hears they're going to be separated, they love their family, they don't come.”
The DOJ inspector general concluded in 2021 that “the Department's single-minded focus on increasing prosecutions came at the expense of careful and appropriate consideration of the impact that prosecution of family unit adults and family separations would have on children traveling with them.” As of March 20, 2024, the federal Family Reunification Task Force had identified 4,656 children separated between January 2017 and January 2021; 3,225 reunifications were confirmed, 71 were in process, and 1,360 children had no confirmed reunification (the task force noted some may have reunified on their own). Figures of 5,400 or more that circulated earlier, including in this entry, are not supported by those records. The 2023 settlement in Ms. L. v. ICE bars the government for eight years from referring a lone parent traveling with a child for prosecution solely for illegal entry. What has happened to these families in Trump's second term is in In Trump's Second Term, a Judge Finds the Government Breached the Family Separation Settlement, and AP Finds Dozens of Children Separated Again.
Correction (October 2, 2026): this entry was rebuilt from primary documents. It previously said more than 5,400 children were separated, a figure no government record supports (the government's count is 4,656), and that Trump ended the policy by executive order; the order largely curtailed it, at least 118 more children were separated afterward, and reunification was ordered by a court. A source about 2019 Border Patrol conditions, unrelated to this policy, and an unverifiable citation were removed.