https://en.wikipedia.org/wiki/Micron_Technology

Micron Technology, Inc. is an American multinational semiconductor company that manufactures computer memory and computer data storage products, including dynamic random-access memory (DRAM), flash memory, High Bandwidth Memory (HBM), and solid-state drives (SSDs). Founded in 1978 in Boise, Idaho, Micron is the only major American computer memory manufacturer.[3] It is one of the "Big Three" computer memory manufacturers, along with the South Korean companies Samsung Electronics and SK Hynix.[4]

They have fabs in the US (and are building more).

https://www.micron.com/us-expansion/

Micron is accelerating its U.S. fab and technology investments, increasing its planned spend to more than $250 billion through 2035, driven by surging demand for memory in the AI era. These investments reflect Micron's confidence in its technology leadership and are designed to support its long-term goal of producing 40% of its DRAM in the U.S. while creating additional good-paying jobs.

Americans do crazy things like not tolerating 24 hour shifts and being required to sleep in a dormitory owned by the employer.

The horrendous workers’ rights in Taiwan and S Korea are not talked about enough when discussing their silicon manufacturing dominance.

Micron says Hi.

Who’s gonna pay for it? A ram fab costs hundreds of billions and takes years to get online, then takes tens of billions every year to constantly upgrade to new standards. And all that for a commodity that while right now is obnoxiously expensive is typically a razor thin margin and sometimes even sold at a loss

There's been a lot of efforts to expand American fabs. Intel, Micron, and TSMC are all working on it (and I'm pretty sure most of those projects have at least broken ground at this point). But even with infinity dollars to spend, it takes a very long time to build these plants. The fabs are similar in size to a "normal" factory, but the entire interior is a series of massive clean rooms that are hundreds if not thousands of times cleaner than an operating room, filled with equipment that is simultaneously very large and very sensitive.

I remember reading somewhere that one of Intel's newest process nodes involves drilling holes measured in hundreds of picometers into the part at some point. A hydrogen atom is roughly 62 picometers across.