And now they live and wait in unfamiliar places: big American suburban houses where no one speaks their language; a locked shelter on a dusty road where they spend little time outside; a converted Walmart where each morning they are required to stand and recite the Pledge of Allegiance, in English, to the country that holds them apart from their parents.

Why must they say those words, some of the children ask at the shelter in Brownsville, on the Mexican border in Texas?

“We tell them, ‘It’s out of respect,’ ” said one employee of the facility, known as Casa Padre, who spoke on the condition of anonymity for fear of losing their job.

U.S. authorities are compiling mug shots of the children in detention. Immigration lawyers who have seen the pictures say some of them show children in tears.