It is extremely unusual for this kind of labor abuse to be carried out by American companies. As the articles note, these are Korean-owned and Korean-operated companies.
FTA: "Korean-operated SL Alabama, finding children as young as age 13."
There are hundreds of foreign owned and operated factories in America that are run like independent kingdoms, staffed with people from other countries with their own restaurants and dorms so the workers are never exposed to the outside world, so that the company can put the all important "Made in USA" label on the product. There's at least one all-Chinese factory outside of Las Vegas. There was a Chinese-run industrial marijuana farming operation shut down in Arizona last year.
And this is not unique to the United States. There are similar operations in Italy, Germany, and elsewhere. There are multiple Chinese factories in Italy churning out "Made in Italy" leather good for the luxury market.
Lots of newspaper articles about it over the last ten years or so.