I have recently been bombarded by comments, many from the same person, insisting that Trump had exactly the same punitive border policy regarding family separation as Presidents Obama and George W. Bush.
The Washington Post fact-checked this claim and found it to be false.
The Washington Post Fact-Checker (Glen Kessler and Salvador Rizzo) reviewed Trump’s recent interview with that newspaper and as usual found many distortions, lies, made-up non-facts. For example, it is not Democrats who are blocking Trump’s big beautiful Wall, but Republicans, who quite sensibly refuse to waste $25 billion on Trump’s signature promise.
Diane Ravitch's blog 
So what did DHS do under the Obama and Bush administrations when adults with children were caught crossing the border illegally? This article says that, except under limited circumstances, such adults and children were not separated. But what happened to those adults and children?