@mglik As for adding companies, either have the company contact me https://americanmadeaudio.com/about-us/ or provide the URL, the categories of products they sell, the location of the factory, and any relevant details.
As for those selling product built abroad, see my comment above regarding "Made in USA" vs. "Assembled in USA." Some companies meet those requirements for a few products, but not for others. While I make all reasonable efforts to point to the right companies, the intent is as a starting point. In the end, each individual buyer will need to determine whether a given company or product is right for them.