> Where in America are these magical semiconductors being made?

You're unaware that the US is one of the world's leading manufacturers of semiconductors?

For 2019 the US exported $44 billion worth of semiconductors. The third largest export for the US, behind airplanes ($130 billion) and oil ($152 billion for all oil products).

There are only a few major semiconductor manufacturing nations and the US is among them.

I took this to be a reference to the original Silicon Valley semiconductor companies. Fairchild etc.

They are referencing Moore's law. Some of them are made in the US, some are not (not today, at least).