Yeni Maricela Gonzalez Garcia stands with her children after she was reunited with her children at the East Harlem Cayuga Centers on July 13, 2018 in New York City.

NEW YORK — The children arrive in groups, sometimes many hours after even an adult's bedtime.

Without their parents, often knowing no English, they're brought by federal agents on journeys as long as 2,000 miles from the southwest U.S. border to social services programs operated by nonprofit, religious or private agencies and companies.