Obama did not put children in “detention cages” as a blanket policy. Reporting and fact-checks indicate that the Obama-era government did detain some families and children in immigration facilities, but the large-scale family separation and “kids in cages” crisis is tied to the Trump administration, not Obama.

What the reporting says

  • During Obama’s presidency, children were sometimes held with parents in family detention, and in limited cases families could be separated for safety or verification reasons.
  • The widely cited figure for Trump-era family separations is about 4,000 children.
  • One report also notes that a detention facility under Obama was expected to hold 480 mothers and children when it opened, with expansion plans later announced.

Direct answer

So the number is not known as a single “Obama had X children in detention cages” figure , because that framing is misleading. The best-supported answer is that Obama-era immigration detention included children in family detention, but the major “children in cages” controversy was not an Obama policy.

TL;DR

The question’s premise is off: Obama did not have a documented mass policy of putting children in detention cages, while Trump’s administration is the one associated with the large-scale separations and “kids in cages” controversy.