Here is a question then:
How much more are you willing to pay?
Is it worth it to you to track down and buy the USA part for +20%, sure. +50%? 100%?
For bearings and such from major parts houses, you will be getting some mexican, chinese, taiwanese, parts and a few USA. Seals and gaskets are often Israeli... oddly enough... as well as mexican/chinese with some American.
If it really matters, I suppose you could track down American ones and stockpile, but if you are asking what parts house carries "Made in the USA" or what major brand that would be... the answer is "None." Federal Mogul, for instance, is just a name kinda like Nike. Their parts are made by the lowest bidder. Some were old FM plants, most aren't. That one company controls..
Federal-Mogul Brands
STEP 1: Choose a Brand
Abex®
AE®
ANCO®
Atlas®
Bentley-Harris®
Beral®
Carter®
Champion®
DURON®
Fel-Pro®
Ferodo®
FP Diesel®
Glyco®
Goetze®
Metafram®
Moog®
National®
Necto®
Nüral®
Payen®
Poral®
Precision®
Sealed Power®
Speed-Pro®
Wagner® Brake
Products
Wagner® Lighting
... as well as house brands for everyone from NAPA to AutoZone.
If you want to be certain you are getting high quality American made products, you have quite a task ahead of you. You will need to open every box and read the markings (If they are even true... ask an aircraft parts man sometime)
Or, you can find a few smaller manufacturers and hope they produce what you need.
I'm an ASE Certified Partsman. I've been in the industry for over 15 years as a tech and counterman. I know what I'm talking about.
The SOP these days is, "Who cares if it's junk? The car or truck it's going on might not be around long enough for this to fail anyway, and if it does, we swap it out under warranty."
Yes, it really is that bad in the industry. Aircraft parts suppliers may be a different story. Some heavy industrial suppliers might still have standards. In the automotive market, there is a quality shortage on the aftermarket side.
Buy the best you can and keep spares handy.