I am assuming the "State" specifically refers to the Wisconsin equivalent of Child Protective Services? I actually have a friend of mine in Utah who works for that state's Child Protective Services, let me ask her if there's anything that you can do on your end.
And the due process used to do this was........
What did the state say was the reason they needed to do so and who signed off on it? Don't tell us your side of the story, tell us the state's side of the story because that's the one that has to be dealt with.
You should have lawyered up before they got this far. It's easier to stop the state before they take action than it is to unravel the muddle they make.