BUDA, Texas (AP) — There were water balloons at Byron Xol's birthday party — bunches of them, filled a dozen at a time. He squeezed them with both hands, until the water burst on his face and chest.

"Super good!" the 9-year-old yelled, again and again.

It's a new catchphrase — but then, Byron spoke no English at all 15 months ago.

It was then that he was packed in a wooden crate by smugglers and shipped from Guatemala to the U.S., only to be grabbed immediately by border agents and ripped away from his father.

His dad was deported. Byron remained, locked away with the thousands of children sep...