> and the US federally owns tons of land it can create manufacturing cities out of

Ok, being generous and accepting your point at face value ....

What about the people staffing those manufacturing cities ? Is the state creating them too ?

I seem to recall reading somewhere that – at most – the US could "find" 200,000 people for new manufacturing plants.

Sounds about right to me, no ?

I think even with a generous mind the US would struggle to "find" much more than that, let alone getting to or exceeding 1 million which is the value you would need for seriously thinking about >1 manufacturing city.