The trek that took Katherine from El Salvador to just steps inside Texas, where she was apprehended by U.S. Border Patrol agents, spanned more than 1,500 miles. But what stands out about that journey in 2009 was something else: Katherine was just 14 years old, and her only companion was her 10-year-old sister Tania. “When [the Border Patrol] picked us up, I began to cry, because I didn’t know what was going to happen to us,” says Katherine, who says she was fleeing an abusive grandmother in El Salvador and hoping to reunite with her mother, who had come to the United States years earlier. (Katherine asked that her last name not be published because some members of her family have an uncertain immigration status.)

Katherine and her sister were at the forefront of what has been a steady increase in unaccompanied youths immigrating to the United States. Three years ago, a little less than 8,000 unaccompanied youths were taken into custody. Last year that figure hit 24,000, and estimates are that the total will exceed 60,000 this year and 100,000 next year. “The number of immigrant children crossing the border is skyrocketing,” says Eve Stotland, director of the Legal Services Center at The Door, a New York-based nonprofit that represents undocumented youth in immigration proceedings. “We are at the beginning of a crisis.”