Yeah, he became American, just like Einstein, Fermi, Von Neumann, etc.
There's a big lesson for Europe there, everyone super productive and able to move to the US does so at the first opportunity.
Yeah, um…
That might have changed somewhat, recently.
When the US is being run by relatively sane people, it's great.
That is not the situation at the moment.
You might want to do a bit more reading on why European intellectuals migrated en masse to the US in the 1930s.