San Marzano tomatoes are being grown in the U.S.? They are traditionally grown in the volcanic soil surrounding Napoli. They are the prescribed tomato for use on truly authentic Neopolitan pizza (there is an association in Napoli which dictates what can and can't be used on certified authentic Neopolitan pizza). They are a less acidic tomato, which makes them great for sauces. You could use them in any other application where you want a good tomato flavor that won't be overbearing.