Strange "proof of identity" questions

Suppose there’s this religious cult living in the woods somewhere in Canada or the U.S… Let’s say they got started in the 1960’s, then kept going for a few decades. And they had a bunch of kids.

Now picture the cult falling apart due to inter-personal conflicts. They lose the land. Suddenly the kids are thrust into the modern world…which requires identification documents.

How would Canadian and American societies handle this, if no record was ever made of their birth (and witnesses were not easily available)? Give them temporary documents? Make them beg in the street? Deport them to Mexico? What?

Can you think of actual cases with a bearing on this? I did read about a man found in Canada who had lost all memory of who he was…but had a British accent, and (this should narrow it down!) knew medieval Latin fluently. Anybody know what happened to him?

Now…what if the cult was not in Canada or America, but in India? But the participants were mostly Canadian and American? And lack documents, etc. How would Western embassies treat their applications for citizenship? The situation of mixed-race offspring of Western troops would be analogous, I suppose–how is that handled? Do the authorities just eyeball them to see if they look foreign, or what?

Not exactly what you’re talking about, but the story of Ishi is an interesting one:

As is the story of Kaspar Hauser:

And here’s a whole list of real life “feral children,” raised by dogs, pigs, monkeys, etc., with their stories.