Just to reiterate what I posted in that other thread (copied below) and to back up what Kirk has posted, the ST719 is manufactured at Sumitomo's Tonawanda New York plant. From what I'm hearing, they are now making most of their commercial line in that Buffalo-area plant.
Same case with Yokohama commercial truck tires. They are made in West Point Mississippi.
Even though we mostly used Toyo for our motorhome replacement tires, I strongly favor all the Japan-based manufacturers for the tires I purchase ...Toyo, Sumitomo, Yokohama, etc. (and Bridgestone before the Firestone merger when they became a first-tier manufacturer). I don't want to pay the premium prices for first tier tires like Michelin, Goodyear, Bridgestone, etc. and neither am I comfortable yet with Chinese manufacturers (plus the political ramifications) so using the tires manufactured by Japan or South Korean based manufacturers would be my first choice ...good quality for prices in the middle of the spectrum. When you can get a tire from a Japanese manufacturer that's made by their U.S. subsidiary like Sumitomo and Yokohama, it's ideal for me.
Off topic anecdote: one of the better cars we've owned is a 2006 Subaru Outback assembled with majority U.S. parts by a subsidiary of a Japanese company in Lafayette Indiana ...it's one of the toads we used and is still sitting around in our garage but it's never had anything go wrong. No major repairs at all and the only money spent was on routine maintenance. It actually feels and drives like the first day we bought it. Sure, just my experience as I know some say the same about their Chevy or Fords but most of my Chevys and Fords have had some major repairs that were required in the first ten years (but I haven't bought a Chevy or Ford lately
post from the other thread:
Sumitomo is one of my favorite brands. As you may or may not know, the Sumitomo company can trace it's roots back to the 1600s and I think is currently in the top 25 largest corporations in Japan.
Their tire and rubber business started in the early 1900s but didn't really get going until the early 1960s. Good news is that the ST719 is now made in their Tonowanda New York plant (Sumitomo Rubber USA, LLC ). So you have a tire that has a huge Japanese corporation behind it but are buying a product that is made in the U.S.A. employing American workers. This is similar to buying a Yokohama truck tire ...another big Japanese company that has a good reputation that has a U.S. subsidiary and a plant in Mississippi that produces commercial truck tires.
Commercial truck tires coming from both those plants have the reputation of having innovative design and top notch quality and engineering.
For me, Sumitomo and Yokohama beat anything coming out of China even if you may have to pay a bit more ...but far less than what you'd pay for a Michelin of similar design.