Are they from the USA? Nowadays, just about all of the tomatoes available at supermarkets—at least in Southern California—are from Mexico, and the same is true for other types of produce. I have been trying to get most of my produce at farmer’s markets.
We have a lot of produce from MX, at our local grocery stores.
It's not unheard of for vendors at a "farmer's market" to buy their produce from wholesalers, so you might be getting Mexican produce anyway.