 One story goes that the first seed of this tomato came to Campania in 1770, as a gift from the Viceroyalty of Peru to the Kingdom of Naples, and that it was planted in the area of San Marzano sul Sarno.In the United States, San Marzano tomatoes are the genetic base for another popular paste tomato, 
the Roma tomato.The Roma is a cross between a San Marzano and two other varieties (one of which was also a San Marzano hybrid) and was introduced by the USDA's Agricultural Research Service in 1955.